638586566811 has 12 divisors (see below), whose sum is σ = 922557843688. Its totient is φ = 425652827904.

The previous prime is 638586566773. The next prime is 638586566887. The reversal of 638586566811 is 118665685836.

It is a happy number.

638586566811 is a `hidden beast` number, since 6 + 3 + 8 + 58 + 6 + 566 + 8 + 11 = 666.

It is not a de Polignac number, because 638586566811 - 2¹⁸ = 638586304667 is a prime.

It is a super-2 number, since 2×638586566811² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638586566411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5905945 + ... + 6013098.

Almost surely, 2^638586566811 is an apocalyptic number.

638586566811 is a deficient number, since it is larger than the sum of its proper divisors (283971276877).

638586566811 is a wasteful number, since it uses less digits than its factorization.

638586566811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11925002 (or 11924999 counting only the distinct ones).

The product of its digits is 49766400, while the sum is 63.

The spelling of 638586566811 in words is "six hundred thirty-eight billion, five hundred eighty-six million, five hundred sixty-six thousand, eight hundred eleven".