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31985211930 = 23573118112713
BaseRepresentation
bin11101110010011101…
…111001101000011010
310001120002211010011220
4131302131321220122
51011001203240210
622405510032510
72211423546510
oct356235715032
9101502733156
1031985211930
1112623900151
126247948736
133029762409
141795d744b0
15c73069c70
hex772779a1a

31985211930 has 128 divisors (see below), whose sum is σ = 90644299776. Its totient is φ = 7068556800.

The previous prime is 31985211911. The next prime is 31985212027. The reversal of 31985211930 is 3911258913.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11788254 + ... + 11790966.

It is an arithmetic number, because the mean of its divisors is an integer number (708158592).

Almost surely, 231985211930 is an apocalyptic number.

31985211930 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31985211930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45322149888).

31985211930 is an abundant number, since it is smaller than the sum of its proper divisors (58659087846).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31985211930 is a wasteful number, since it uses less digits than its factorization.

31985211930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4572.

The product of its (nonzero) digits is 58320, while the sum is 42.

The spelling of 31985211930 in words is "thirty-one billion, nine hundred eighty-five million, two hundred eleven thousand, nine hundred thirty".

Divisors: 1 2 3 5 6 7 10 14 15 21 30 31 35 42 62 70 93 105 155 186 210 217 310 434 465 651 930 1085 1302 1811 2170 2713 3255 3622 5426 5433 6510 8139 9055 10866 12677 13565 16278 18110 18991 25354 27130 27165 37982 38031 40695 54330 56141 56973 63385 76062 81390 84103 94955 112282 113946 126770 168206 168423 189910 190155 252309 280705 284865 336846 380310 392987 420515 504618 561410 569730 588721 785974 841030 842115 1177442 1178961 1261545 1684230 1766163 1964935 2357922 2523090 2943605 3532326 3929870 4913243 5887210 5894805 8830815 9826486 11789610 14739729 17661630 24566215 29479458 34392701 49132430 68785402 73698645 103178103 147397290 152310533 171963505 206356206 304621066 343927010 456931599 515890515 761552665 913863198 1031781030 1066173731 1523105330 2132347462 2284657995 3198521193 4569315990 5330868655 6397042386 10661737310 15992605965 31985211930