165621121068 has 48 divisors (see below), whose sum is σ = 416275222496. Its totient is φ = 50948213760.

The previous prime is 165621121049. The next prime is 165621121069. The reversal of 165621121068 is 860121126561.

It is a super-2 number, since 2×165621121068² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (165621121069) 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 15 ways as a sum of consecutive naturals, for example, 542358 + ... + 790818.

Almost surely, 2^165621121068 is an apocalyptic number.

It is an amenable number.

165621121068 is an abundant number, since it is smaller than the sum of its proper divisors (250654101428).

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

165621121068 is a wasteful number, since it uses less digits than its factorization.

165621121068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252754 (or 252752 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The spelling of 165621121068 in words is "one hundred sixty-five billion, six hundred twenty-one million, one hundred twenty-one thousand, sixty-eight".