639712431 has 32 divisors (see below), whose sum is σ = 1011225600. Its totient is φ = 398286720.

The previous prime is 639712391. The next prime is 639712439. The reversal of 639712431 is 134217936.

639712431 is a `hidden beast` number, since 639 + 7 + 12 + 4 + 3 + 1 = 666.

639712431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639712431 - 2¹³ = 639704239 is a prime.

It is a super-2 number, since 2×639712431² = 818463988751859522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639712439) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54810 + ... + 65448.

It is an arithmetic number, because the mean of its divisors is an integer number (31600800).

Almost surely, 2^639712431 is an apocalyptic number.

639712431 is a deficient number, since it is larger than the sum of its proper divisors (371513169).

639712431 is a wasteful number, since it uses less digits than its factorization.

639712431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10796 (or 10790 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 639712431 is about 25292.5370613547. The cubic root of 639712431 is about 861.6447840449.

The spelling of 639712431 in words is "six hundred thirty-nine million, seven hundred twelve thousand, four hundred thirty-one".