166515641890400 has 72 divisors (see below), whose sum is σ = 443461429948824. Its totient is φ = 60551142502400.

The previous prime is 166515641890397. The next prime is 166515641890427. The reversal of 166515641890400 is 4098146515661.

It is a happy number.

It is a super-2 number, since 2×166515641890400² (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 11 ways as a sum of consecutive naturals, for example, 9461107217 + ... + 9461124816.

It is an arithmetic number, because the mean of its divisors is an integer number (6159186527067).

Almost surely, 2^{166515641890400} is an apocalyptic number.

166515641890400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166515641890400 is an abundant number, since it is smaller than the sum of its proper divisors (276945788058424).

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

166515641890400 is a wasteful number, since it uses less digits than its factorization.

166515641890400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18922232064 (or 18922232051 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 56.

The spelling of 166515641890400 in words is "one hundred sixty-six trillion, five hundred fifteen billion, six hundred forty-one million, eight hundred ninety thousand, four hundred".