638086680 has 256 divisors, whose sum is σ = 2652134400. Its totient is φ = 132572160.

The previous prime is 638086643. The next prime is 638086697. The reversal of 638086680 is 86680836.

638086680 is a `hidden beast` number, since 638 + 0 + 8 + 6 + 6 + 8 + 0 = 666.

It is a super-2 number, since 2×638086680² = 814309222386844800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 79324 + ... + 86996.

It is an arithmetic number, because the mean of its divisors is an integer number (10359900).

Almost surely, 2^638086680 is an apocalyptic number.

638086680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638086680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1326067200).

638086680 is an abundant number, since it is smaller than the sum of its proper divisors (2014047720).

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

638086680 is a wasteful number, since it uses less digits than its factorization.

638086680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7711 (or 7701 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 638086680 is about 25260.3776693857. The cubic root of 638086680 is about 860.9142431797.

The spelling of 638086680 in words is "six hundred thirty-eight million, eighty-six thousand, six hundred eighty".