638271614640 has 320 divisors, whose sum is σ = 2241833656320. Its totient is φ = 148871838720.

The previous prime is 638271614597. The next prime is 638271614653. The reversal of 638271614640 is 46416172836.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 638271614640.

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 63 ways as a sum of consecutive naturals, for example, 7277127 + ... + 7364313.

It is an arithmetic number, because the mean of its divisors is an integer number (7005730176).

Almost surely, 2^638271614640 is an apocalyptic number.

638271614640 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 638271614640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120916828160).

638271614640 is an abundant number, since it is smaller than the sum of its proper divisors (1603562041680).

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

638271614640 is a wasteful number, since it uses less digits than its factorization.

638271614640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87320 (or 87314 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The spelling of 638271614640 in words is "six hundred thirty-eight billion, two hundred seventy-one million, six hundred fourteen thousand, six hundred forty".