166561506616056 has 32 divisors (see below), whose sum is σ = 424260441383760. Its totient is φ = 54472945559552.

The previous prime is 166561506615941. The next prime is 166561506616067. The reversal of 166561506616056 is 650616605165661.

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, 65472289065 + ... + 65472291608.

Almost surely, 2^{166561506616056} is an apocalyptic number.

It is an amenable number.

166561506616056 is an abundant number, since it is smaller than the sum of its proper divisors (257698934767704).

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

166561506616056 is a wasteful number, since it uses less digits than its factorization.

166561506616056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130944580735 (or 130944580731 counting only the distinct ones).

The product of its (nonzero) digits is 34992000, while the sum is 60.

The spelling of 166561506616056 in words is "one hundred sixty-six trillion, five hundred sixty-one billion, five hundred six million, six hundred sixteen thousand, fifty-six".