165620631 has 32 divisors (see below), whose sum is σ = 259522560. Its totient is φ = 92901600.

The previous prime is 165620627. The next prime is 165620639. The reversal of 165620631 is 136026561.

It is not a de Polignac number, because 165620631 - 2² = 165620627 is a prime.

It is a super-2 number, since 2×165620631² = 54860386825676322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165620639) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20010 + ... + 27048.

It is an arithmetic number, because the mean of its divisors is an integer number (8110080).

Almost surely, 2^165620631 is an apocalyptic number.

165620631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

165620631 is a deficient number, since it is larger than the sum of its proper divisors (93901929).

165620631 is a wasteful number, since it uses less digits than its factorization.

165620631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7107.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 165620631 is about 12869.3679331970. The cubic root of 165620631 is about 549.1674798665.

The spelling of 165620631 in words is "one hundred sixty-five million, six hundred twenty thousand, six hundred thirty-one".