166156507220025 has 48 divisors (see below), whose sum is σ = 324782768822400. Its totient is φ = 73338044559360.

The previous prime is 166156507220017. The next prime is 166156507220063. The reversal of 166156507220025 is 520022705651661.

It is not a de Polignac number, because 166156507220025 - 2³ = 166156507220017 is a prime.

It is a super-2 number, since 2×166156507220025² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5456684520 + ... + 5456714969.

It is an arithmetic number, because the mean of its divisors is an integer number (6766307683800).

Almost surely, 2^{166156507220025} is an apocalyptic number.

166156507220025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166156507220025 is a deficient number, since it is larger than the sum of its proper divisors (158626261602375).

166156507220025 is a wasteful number, since it uses less digits than its factorization.

166156507220025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10913399538 (or 10913399533 counting only the distinct ones).

The product of its (nonzero) digits is 1512000, while the sum is 48.

The spelling of 166156507220025 in words is "one hundred sixty-six trillion, one hundred fifty-six billion, five hundred seven million, two hundred twenty thousand, twenty-five".