639245056623616 has 99 divisors (see below), whose sum is σ = 1283752367804613. Its totient is φ = 318156906209280.

The previous prime is 639245056623601. The next prime is 639245056623629. The reversal of 639245056623616 is 616326650542936.

The square root of 639245056623616 is 25283296.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 129817766937600 + 509427289686016 = 11393760^2 + 22570496^2 .

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 188512253281 + ... + 188512256671.

Almost surely, 2^{639245056623616} is an apocalyptic number.

639245056623616 is the 25283296-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639245056623616

639245056623616 is an abundant number, since it is smaller than the sum of its proper divisors (644507311180997).

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

639245056623616 is an frugal number, since it uses more digits than its factorization.

639245056623616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7268 (or 3626 counting only the distinct ones).

The product of its (nonzero) digits is 251942400, while the sum is 64.

639245056623616 divided by its sum of digits (64) gives a square (9988204009744 = 3160412²).

The spelling of 639245056623616 in words is "six hundred thirty-nine trillion, two hundred forty-five billion, fifty-six million, six hundred twenty-three thousand, six hundred sixteen".