638865682260 has 48 divisors (see below), whose sum is σ = 1926425751936. Its totient is φ = 157259244672.

The previous prime is 638865682241. The next prime is 638865682283. The reversal of 638865682260 is 62286568836.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 638865682194 and 638865682203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 409528504 + ... + 409530063.

It is an arithmetic number, because the mean of its divisors is an integer number (40133869832).

Almost surely, 2^638865682260 is an apocalyptic number.

638865682260 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638865682260 is an abundant number, since it is smaller than the sum of its proper divisors (1287560069676).

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

638865682260 is a wasteful number, since it uses less digits than its factorization.

638865682260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819058592 (or 819058590 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 60.

It can be divided in two parts, 638865 and 682260, that added together give a triangular number (1321125 = T₁₆₂₅).

The spelling of 638865682260 in words is "six hundred thirty-eight billion, eight hundred sixty-five million, six hundred eighty-two thousand, two hundred sixty".