639954576 has 180 divisors, whose sum is σ = 1939764736. Its totient is φ = 196732800.

The previous prime is 639954563. The next prime is 639954643. The reversal of 639954576 is 675459936.

639954576 is a `hidden beast` number, since 6 + 3 + 99 + 545 + 7 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2361321 + ... + 2361591.

Almost surely, 2^639954576 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639954576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (969882368).

639954576 is an abundant number, since it is smaller than the sum of its proper divisors (1299810160).

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

639954576 is a wasteful number, since it uses less digits than its factorization.

639954576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 330 counting only the distinct ones).

The product of its digits is 6123600, while the sum is 54.

The square root of 639954576 is about 25297.3234947889. The cubic root of 639954576 is about 861.7534873968.

Subtracting from 639954576 its product of digits (6123600), we obtain a square (633830976 = 25176²).

The spelling of 639954576 in words is "six hundred thirty-nine million, nine hundred fifty-four thousand, five hundred seventy-six".