165121959168 has 432 divisors, whose sum is σ = 507835560960. Its totient is φ = 51492519936.

The previous prime is 165121959127. The next prime is 165121959193. The reversal of 165121959168 is 861959121561.

It is a happy number.

165121959168 is a `hidden beast` number, since 1 + 6 + 512 + 19 + 59 + 1 + 68 = 666.

It is a super-2 number, since 2×165121959168² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 740457105 + ... + 740457327.

It is an arithmetic number, because the mean of its divisors is an integer number (1175545280).

Almost surely, 2^165121959168 is an apocalyptic number.

165121959168 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165121959168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253917780480).

165121959168 is an abundant number, since it is smaller than the sum of its proper divisors (342713601792).

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

165121959168 is a wasteful number, since it uses less digits than its factorization.

165121959168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514 (or 497 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 54.

The spelling of 165121959168 in words is "one hundred sixty-five billion, one hundred twenty-one million, nine hundred fifty-nine thousand, one hundred sixty-eight".