639715542 has 16 divisors (see below), whose sum is σ = 1354691952. Its totient is φ = 200695040.

The previous prime is 639715529. The next prime is 639715547. The reversal of 639715542 is 245517936.

It is a junction number, because it is equal to n+sod(n) for n = 639715494 and 639715503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639715547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3135759 + ... + 3135962.

It is an arithmetic number, because the mean of its divisors is an integer number (84668247).

Almost surely, 2^639715542 is an apocalyptic number.

639715542 is an abundant number, since it is smaller than the sum of its proper divisors (714976410).

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

639715542 is a wasteful number, since it uses less digits than its factorization.

639715542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6271743.

The product of its digits is 226800, while the sum is 42.

The square root of 639715542 is about 25292.5985616346. The cubic root of 639715542 is about 861.6461808040.

The spelling of 639715542 in words is "six hundred thirty-nine million, seven hundred fifteen thousand, five hundred forty-two".