165907293921 has 24 divisors (see below), whose sum is σ = 247617027840. Its totient is φ = 106931944800.

The previous prime is 165907293919. The next prime is 165907293949. The reversal of 165907293921 is 129392709561.

165907293921 is a `hidden beast` number, since 1 + 6 + 590 + 7 + 29 + 3 + 9 + 21 = 666.

It is not a de Polignac number, because 165907293921 - 2¹ = 165907293919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165907293221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6351 + ... + 576068.

It is an arithmetic number, because the mean of its divisors is an integer number (10317376160).

Almost surely, 2^165907293921 is an apocalyptic number.

It is an amenable number.

165907293921 is a deficient number, since it is larger than the sum of its proper divisors (81709733919).

165907293921 is a wasteful number, since it uses less digits than its factorization.

165907293921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583477 (or 583474 counting only the distinct ones).

The product of its (nonzero) digits is 1837080, while the sum is 54.

The spelling of 165907293921 in words is "one hundred sixty-five billion, nine hundred seven million, two hundred ninety-three thousand, nine hundred twenty-one".