638822561865 has 32 divisors (see below), whose sum is σ = 1083603495936. Its totient is φ = 320803649280.

The previous prime is 638822561857. The next prime is 638822561873. The reversal of 638822561865 is 568165228836.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (638822561857) and next prime (638822561873).

It is not a de Polignac number, because 638822561865 - 2³ = 638822561857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 638822561799 and 638822561808.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18547822 + ... + 18582231.

It is an arithmetic number, because the mean of its divisors is an integer number (33862609248).

Almost surely, 2^638822561865 is an apocalyptic number.

It is an amenable number.

638822561865 is a deficient number, since it is larger than the sum of its proper divisors (444780934071).

638822561865 is a wasteful number, since it uses less digits than its factorization.

638822561865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37130129.

The product of its digits is 33177600, while the sum is 60.

The spelling of 638822561865 in words is "six hundred thirty-eight billion, eight hundred twenty-two million, five hundred sixty-one thousand, eight hundred sixty-five".