639115264 has 28 divisors (see below), whose sum is σ = 1278168894. Its totient is φ = 319553536.

The previous prime is 639115241. The next prime is 639115271. The reversal of 639115264 is 462511936.

It can be written as a sum of positive squares in only one way, i.e., 639078400 + 36864 = 25280^2 + 192^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30817 + ... + 47200.

Almost surely, 2^639115264 is an apocalyptic number.

639115264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

639115264 is a deficient number, since it is larger than the sum of its proper divisors (639053630).

639115264 is an frugal number, since it uses more digits than its factorization.

639115264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78043 (or 78019 counting only the distinct ones).

The product of its digits is 38880, while the sum is 37.

The square root of 639115264 is about 25280.7291034100. The cubic root of 639115264 is about 861.3765874839.

The spelling of 639115264 in words is "six hundred thirty-nine million, one hundred fifteen thousand, two hundred sixty-four".