638407380776 has 24 divisors (see below), whose sum is σ = 1315725957210. Its totient is φ = 290185172640.

The previous prime is 638407380773. The next prime is 638407380883. The reversal of 638407380776 is 677083704836.

It can be written as a sum of positive squares in only one way, i.e., 593476099876 + 44931280900 = 770374^2 + 211970^2 .

It is not an unprimeable number, because it can be changed into a prime (638407380773) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 329754911 + ... + 329756846.

Almost surely, 2^638407380776 is an apocalyptic number.

It is an amenable number.

638407380776 is an abundant number, since it is smaller than the sum of its proper divisors (677318576434).

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

638407380776 is a wasteful number, since it uses less digits than its factorization.

638407380776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659511785 (or 659511770 counting only the distinct ones).

The product of its (nonzero) digits is 28449792, while the sum is 59.

The spelling of 638407380776 in words is "six hundred thirty-eight billion, four hundred seven million, three hundred eighty thousand, seven hundred seventy-six".