18621563634 has 32 divisors (see below), whose sum is σ = 41421905280. Its totient is φ = 6201090000.

The previous prime is 18621563629. The next prime is 18621563663. The reversal of 18621563634 is 43636512681.

18621563634 is a `hidden beast` number, since 1 + 8 + 6 + 2 + 1 + 5 + 6 + 3 + 634 = 666.

It is a super-2 number, since 2×18621563634² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18621563634.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113742 + ... + 224009.

It is an arithmetic number, because the mean of its divisors is an integer number (1294434540).

Almost surely, 2^18621563634 is an apocalyptic number.

18621563634 is an abundant number, since it is smaller than the sum of its proper divisors (22800341646).

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

18621563634 is a wasteful number, since it uses less digits than its factorization.

18621563634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338783 (or 338777 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The spelling of 18621563634 in words is "eighteen billion, six hundred twenty-one million, five hundred sixty-three thousand, six hundred thirty-four".