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31021431 = 372117001
BaseRepresentation
bin111011001010…
…1100101110111
32011101001101220
41312111211313
530420141211
63024521423
7524451330
oct166254567
964331356
1031021431
1116568951
12a480273
136571b9c
144197287
152acb806
hex1d95977

31021431 has 16 divisors (see below), whose sum is σ = 47501568. Its totient is φ = 17640000.

The previous prime is 31021427. The next prime is 31021493. The reversal of 31021431 is 13412013.

It is not a de Polignac number, because 31021431 - 22 = 31021427 is a prime.

It is a super-2 number, since 2×310214312 = 1924658362575522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31021431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31021931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 931 + ... + 7931.

It is an arithmetic number, because the mean of its divisors is an integer number (2968848).

Almost surely, 231021431 is an apocalyptic number.

31021431 is a deficient number, since it is larger than the sum of its proper divisors (16480137).

31021431 is a wasteful number, since it uses less digits than its factorization.

31021431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7222.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 31021431 is about 5569.6885909358. The cubic root of 31021431 is about 314.2104388099.

Adding to 31021431 its reverse (13412013), we get a palindrome (44433444).

The spelling of 31021431 in words is "thirty-one million, twenty-one thousand, four hundred thirty-one".

Divisors: 1 3 7 21 211 633 1477 4431 7001 21003 49007 147021 1477211 4431633 10340477 31021431