639129612 has 96 divisors (see below), whose sum is σ = 1711632384. Its totient is φ = 183726400.

The previous prime is 639129577. The next prime is 639129613. The reversal of 639129612 is 216921936.

It is a super-3 number, since 3×639129612³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (639129613) 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, 396913 + ... + 398519.

It is an arithmetic number, because the mean of its divisors is an integer number (17829504).

Almost surely, 2^639129612 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 639129612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (855816192).

639129612 is an abundant number, since it is smaller than the sum of its proper divisors (1072502772).

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

639129612 is a wasteful number, since it uses less digits than its factorization.

639129612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779 (or 1777 counting only the distinct ones).

The product of its digits is 34992, while the sum is 39.

The square root of 639129612 is about 25281.0128752786. The cubic root of 639129612 is about 861.3830333419.

The spelling of 639129612 in words is "six hundred thirty-nine million, one hundred twenty-nine thousand, six hundred twelve".