166721655020120 has 32 divisors (see below), whose sum is σ = 375214575153600. Its totient is φ = 66672510655488.

The previous prime is 166721655020099. The next prime is 166721655020191. The reversal of 166721655020120 is 21020556127661.

It is a super-2 number, since 2×166721655020120² (a number of 29 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 7 ways as a sum of consecutive naturals, for example, 504562544 + ... + 504892863.

It is an arithmetic number, because the mean of its divisors is an integer number (11725455473550).

Almost surely, 2^{166721655020120} is an apocalyptic number.

166721655020120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166721655020120 is an abundant number, since it is smaller than the sum of its proper divisors (208492920133480).

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

166721655020120 is a wasteful number, since it uses less digits than its factorization.

166721655020120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1009459547 (or 1009459543 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 44.

The spelling of 166721655020120 in words is "one hundred sixty-six trillion, seven hundred twenty-one billion, six hundred fifty-five million, twenty thousand, one hundred twenty".