166565155420 has 24 divisors (see below), whose sum is σ = 349860067200. Its totient is φ = 66612111552.

The previous prime is 166565155411. The next prime is 166565155433. The reversal of 166565155420 is 24551565661.

It is a happy number.

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, 773740 + ... + 965299.

It is an arithmetic number, because the mean of its divisors is an integer number (14577502800).

Almost surely, 2^166565155420 is an apocalyptic number.

166565155420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166565155420 is an abundant number, since it is smaller than the sum of its proper divisors (183294911780).

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

166565155420 is a wasteful number, since it uses less digits than its factorization.

166565155420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1743837 (or 1743835 counting only the distinct ones).

The product of its (nonzero) digits is 1080000, while the sum is 46.

The spelling of 166565155420 in words is "one hundred sixty-six billion, five hundred sixty-five million, one hundred fifty-five thousand, four hundred twenty".