639474457 has 16 divisors (see below), whose sum is σ = 662618880. Its totient is φ = 616770000.

The previous prime is 639474449. The next prime is 639474467. The reversal of 639474457 is 754474936.

639474457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 639474457 - 2³ = 639474449 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639474457.

It is not an unprimeable number, because it can be changed into a prime (639474467) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1931782 + ... + 1932112.

It is an arithmetic number, because the mean of its divisors is an integer number (41413680).

Almost surely, 2^639474457 is an apocalyptic number.

It is an amenable number.

639474457 is a deficient number, since it is larger than the sum of its proper divisors (23144423).

639474457 is a wasteful number, since it uses less digits than its factorization.

639474457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804.

The product of its digits is 2540160, while the sum is 49.

The square root of 639474457 is about 25287.8321925783. The cubic root of 639474457 is about 861.5379264021.

The spelling of 639474457 in words is "six hundred thirty-nine million, four hundred seventy-four thousand, four hundred fifty-seven".