639605474 has 16 divisors (see below), whose sum is σ = 1015147680. Its totient is φ = 301397760.

The previous prime is 639605471. The next prime is 639605497. The reversal of 639605474 is 474506936.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (639605471) 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, 36272 + ... + 50939.

It is an arithmetic number, because the mean of its divisors is an integer number (63446730).

Almost surely, 2^639605474 is an apocalyptic number.

639605474 is a deficient number, since it is larger than the sum of its proper divisors (375542206).

639605474 is a wasteful number, since it uses less digits than its factorization.

639605474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87425.

The product of its (nonzero) digits is 544320, while the sum is 44.

The square root of 639605474 is about 25290.4225745637. The cubic root of 639605474 is about 861.5967603427.

The spelling of 639605474 in words is "six hundred thirty-nine million, six hundred five thousand, four hundred seventy-four".