638865331260 has 96 divisors (see below), whose sum is σ = 1934837567040. Its totient is φ = 156572393472.

The previous prime is 638865331243. The next prime is 638865331301. The reversal of 638865331260 is 62133568836.

It is a happy number.

It is a super-2 number, since 2×638865331260² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1609717 + ... + 1966956.

It is an arithmetic number, because the mean of its divisors is an integer number (20154557990).

Almost surely, 2^638865331260 is an apocalyptic number.

638865331260 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638865331260 is an abundant number, since it is smaller than the sum of its proper divisors (1295972235780).

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

638865331260 is a wasteful number, since it uses less digits than its factorization.

638865331260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3576927 (or 3576925 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 51.

The spelling of 638865331260 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, three hundred thirty-one thousand, two hundred sixty".