638407217877 has 64 divisors (see below), whose sum is σ = 1012968633600. Its totient is φ = 352551813120.

The previous prime is 638407217863. The next prime is 638407217923. The reversal of 638407217877 is 778712704836.

It is not a de Polignac number, because 638407217877 - 2⁶ = 638407217813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638407217877.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638407217807) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12553333 + ... + 12604085.

It is an arithmetic number, because the mean of its divisors is an integer number (15827634900).

Almost surely, 2^638407217877 is an apocalyptic number.

It is an amenable number.

638407217877 is a deficient number, since it is larger than the sum of its proper divisors (374561415723).

638407217877 is a wasteful number, since it uses less digits than its factorization.

638407217877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51158.

The product of its (nonzero) digits is 22127616, while the sum is 60.

The spelling of 638407217877 in words is "six hundred thirty-eight billion, four hundred seven million, two hundred seventeen thousand, eight hundred seventy-seven".