166156563818 has 24 divisors (see below), whose sum is σ = 295396564932. Its totient is φ = 69866369664.

The previous prime is 166156563809. The next prime is 166156563827. The reversal of 166156563818 is 818365651661.

It is an interprime number because it is at equal distance from previous prime (166156563809) and next prime (166156563827).

It can be written as a sum of positive squares in 2 ways, for example, as 165296725489 + 859838329 = 406567^2 + 29323^2 .

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, 15989855 + ... + 16000242.

Almost surely, 2^166156563818 is an apocalyptic number.

166156563818 is a deficient number, since it is larger than the sum of its proper divisors (129240001114).

166156563818 is a wasteful number, since it uses less digits than its factorization.

166156563818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31990166 (or 31990159 counting only the distinct ones).

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

The spelling of 166156563818 in words is "one hundred sixty-six billion, one hundred fifty-six million, five hundred sixty-three thousand, eight hundred eighteen".