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20437847521 = 7213215712
BaseRepresentation
bin10011000010001100…
…001100110111100001
31221202100102020010121
4103002030030313201
5313324042110041
613220010000241
71322316560200
oct230214146741
957670366117
1020437847521
1187386a5383
123b64716081
131c0930b100
14dbc4dd237
157e94087d1
hex4c230cde1

20437847521 has 27 divisors (see below), whose sum is σ = 25760533203. Its totient is φ = 16160311440.

The previous prime is 20437847513. The next prime is 20437847581. The reversal of 20437847521 is 12574873402.

The square root of 20437847521 is 142961.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3023350225 + 17414497296 = 54985^2 + 131964^2 .

It is not a de Polignac number, because 20437847521 - 23 = 20437847513 is a prime.

It is a super-2 number, since 2×204378475212 (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20437847581) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 13008666 + ... + 13010236.

Almost surely, 220437847521 is an apocalyptic number.

20437847521 is the 142961-st square number.

20437847521 is the 71481-st centered octagonal number.

It is an amenable number.

20437847521 is a deficient number, since it is larger than the sum of its proper divisors (5322685682).

20437847521 is an frugal number, since it uses more digits than its factorization.

20437847521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3182 (or 1591 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 43.

The spelling of 20437847521 in words is "twenty billion, four hundred thirty-seven million, eight hundred forty-seven thousand, five hundred twenty-one".

Divisors: 1 7 13 49 91 169 637 1183 1571 8281 10997 20423 76979 142961 265499 1000727 1858493 2468041 13009451 17276287 32084533 120934009 224591731 417098929 1572142117 2919692503 20437847521