639867312 has 120 divisors (see below), whose sum is σ = 2066764544. Its totient is φ = 181014912.

The previous prime is 639867299. The next prime is 639867323. The reversal of 639867312 is 213768936.

639867312 is a `hidden beast` number, since 639 + 8 + 6 + 7 + 3 + 1 + 2 = 666.

It is a super-2 number, since 2×639867312² = 818860353932210688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 100743 + ... + 106905.

Almost surely, 2^639867312 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 639867312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1033382272).

639867312 is an abundant number, since it is smaller than the sum of its proper divisors (1426897232).

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

639867312 is a wasteful number, since it uses less digits than its factorization.

639867312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6287 (or 6278 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 639867312 is about 25295.5986685431. The cubic root of 639867312 is about 861.7143161402.

The spelling of 639867312 in words is "six hundred thirty-nine million, eight hundred sixty-seven thousand, three hundred twelve".