166622635538 has 54 divisors (see below), whose sum is σ = 267027217821. Its totient is φ = 77973553728.

The previous prime is 166622635523. The next prime is 166622635547. The reversal of 166622635538 is 835536226661.

It can be written as a sum of positive squares in 14 ways, for example, as 360126529 + 166262509009 = 18977^2 + 407753^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=288637.

It is a self number, because there is not a number n which added to its sum of digits gives 166622635538.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 619414868 + ... + 619415136.

Almost surely, 2^166622635538 is an apocalyptic number.

166622635538 is a deficient number, since it is larger than the sum of its proper divisors (100404582283).

166622635538 is an frugal number, since it uses more digits than its factorization.

166622635538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672 (or 337 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 53.

The spelling of 166622635538 in words is "one hundred sixty-six billion, six hundred twenty-two million, six hundred thirty-five thousand, five hundred thirty-eight".