639672 has 32 divisors (see below), whose sum is σ = 1745280. Its totient is φ = 193760.

The previous prime is 639671. The next prime is 639677. The reversal of 639672 is 276936.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639671) 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, 948 + ... + 1475.

It is an arithmetic number, because the mean of its divisors is an integer number (54540).

2⁶³⁹⁶⁷² is an apocalyptic number.

It is an amenable number.

639672 is an abundant number, since it is smaller than the sum of its proper divisors (1105608).

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

639672 is a wasteful number, since it uses less digits than its factorization.

639672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443 (or 2439 counting only the distinct ones).

The product of its digits is 13608, while the sum is 33.

The square root of 639672 is about 799.7949737276. The cubic root of 639672 is about 86.1626631152.

The spelling of 639672 in words is "six hundred thirty-nine thousand, six hundred seventy-two".