165221161065700 has 36 divisors (see below), whose sum is σ = 358532739384820. Its totient is φ = 66087944634240.

The previous prime is 165221161065691. The next prime is 165221161065721. The reversal of 165221161065700 is 7560161122561.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 7389578950884 + 157831582114816 = 2718378^2 + 12563104^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6408106 + ... + 19274494.

Almost surely, 2^{165221161065700} is an apocalyptic number.

165221161065700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165221161065700 is an abundant number, since it is smaller than the sum of its proper divisors (193311578319120).

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

165221161065700 is a wasteful number, since it uses less digits than its factorization.

165221161065700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12994816 (or 12994809 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 165221161065700 in words is "one hundred sixty-five trillion, two hundred twenty-one billion, one hundred sixty-one million, sixty-five thousand, seven hundred".