639132386 has 4 divisors (see below), whose sum is σ = 958698582. Its totient is φ = 319566192.

The previous prime is 639132379. The next prime is 639132409. The reversal of 639132386 is 683231936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 611622361 + 27510025 = 24731^2 + 5245^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159783095 + ... + 159783098.

Almost surely, 2^639132386 is an apocalyptic number.

639132386 is a deficient number, since it is larger than the sum of its proper divisors (319566196).

639132386 is a wasteful number, since it uses less digits than its factorization.

639132386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319566195.

The product of its digits is 139968, while the sum is 41.

The square root of 639132386 is about 25281.0677385272. The cubic root of 639132386 is about 861.3842795539.

The spelling of 639132386 in words is "six hundred thirty-nine million, one hundred thirty-two thousand, three hundred eighty-six".