639243862 has 4 divisors (see below), whose sum is σ = 958865796. Its totient is φ = 319621930.

The previous prime is 639243841. The next prime is 639243863. The reversal of 639243862 is 268342936.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639243863) by changing a digit.

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 as a sum of consecutive naturals, namely, 159810964 + ... + 159810967.

It is an arithmetic number, because the mean of its divisors is an integer number (239716449).

Almost surely, 2^639243862 is an apocalyptic number.

639243862 is a deficient number, since it is larger than the sum of its proper divisors (319621934).

639243862 is a wasteful number, since it uses less digits than its factorization.

639243862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319621933.

The product of its digits is 373248, while the sum is 43.

The square root of 639243862 is about 25283.2723752286. The cubic root of 639243862 is about 861.4343568639.

The spelling of 639243862 in words is "six hundred thirty-nine million, two hundred forty-three thousand, eight hundred sixty-two".