639542373 has 8 divisors (see below), whose sum is σ = 875769888. Its totient is φ = 414838224.

The previous prime is 639542357. The next prime is 639542377. The reversal of 639542373 is 373245936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 639542373 - 2⁴ = 639542357 is a prime.

It is a super-2 number, since 2×639542373² = 818028893724942258, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639542377) 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, 2880711 + ... + 2880932.

It is an arithmetic number, because the mean of its divisors is an integer number (109471236).

Almost surely, 2^639542373 is an apocalyptic number.

It is an amenable number.

639542373 is a deficient number, since it is larger than the sum of its proper divisors (236227515).

639542373 is a wasteful number, since it uses less digits than its factorization.

639542373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5761683.

The product of its digits is 408240, while the sum is 42.

The square root of 639542373 is about 25289.1750162001. The cubic root of 639542373 is about 861.5684254772.

The spelling of 639542373 in words is "six hundred thirty-nine million, five hundred forty-two thousand, three hundred seventy-three".