639974601 has 20 divisors (see below), whose sum is σ = 1092585472. Its totient is φ = 365699448.

The previous prime is 639974591. The next prime is 639974603. The reversal of 639974601 is 106479936.

639974601 is a `hidden beast` number, since 6 + 39 + 9 + 7 + 4 + 601 = 666.

It is not a de Polignac number, because 639974601 - 2¹³ = 639966409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639974603) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 563785 + ... + 564918.

Almost surely, 2^639974601 is an apocalyptic number.

It is an amenable number.

639974601 is a deficient number, since it is larger than the sum of its proper divisors (452610871).

639974601 is a wasteful number, since it uses less digits than its factorization.

639974601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128722 (or 1128713 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 639974601 is about 25297.7192845521. The cubic root of 639974601 is about 861.7624757605.

The spelling of 639974601 in words is "six hundred thirty-nine million, nine hundred seventy-four thousand, six hundred one".