639472 has 20 divisors (see below), whose sum is σ = 1312416. Its totient is φ = 300800.

The previous prime is 639451. The next prime is 639487. The reversal of 639472 is 274936.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 904 + ... + 1447.

2⁶³⁹⁴⁷² is an apocalyptic number.

It is an amenable number.

639472 is an abundant number, since it is smaller than the sum of its proper divisors (672944).

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

639472 is a wasteful number, since it uses less digits than its factorization.

639472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2376 (or 2370 counting only the distinct ones).

The product of its digits is 9072, while the sum is 31.

The square root of 639472 is about 799.6699319094. The cubic root of 639472 is about 86.1536822995.

It can be divided in two parts, 639 and 472, that added together give a palindrome (1111).

The spelling of 639472 in words is "six hundred thirty-nine thousand, four hundred seventy-two".