639712 has 12 divisors (see below), whose sum is σ = 1259496. Its totient is φ = 319840.

The previous prime is 639703. The next prime is 639713. The reversal of 639712 is 217936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9964 + ... + 10027.

It is an arithmetic number, because the mean of its divisors is an integer number (104958).

2⁶³⁹⁷¹² is an apocalyptic number.

It is an amenable number.

639712 is a deficient number, since it is larger than the sum of its proper divisors (619784).

639712 is a wasteful number, since it uses less digits than its factorization.

639712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20001 (or 19993 counting only the distinct ones).

The product of its digits is 2268, while the sum is 28.

The square root of 639712 is about 799.8199797454. The cubic root of 639712 is about 86.1644590537.

The spelling of 639712 in words is "six hundred thirty-nine thousand, seven hundred twelve".