639662 has 4 divisors (see below), whose sum is σ = 959496. Its totient is φ = 319830.

The previous prime is 639647. The next prime is 639671. The reversal of 639662 is 266936.

639662 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

639662 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159914 + ... + 159917.

It is an arithmetic number, because the mean of its divisors is an integer number (239874).

2⁶³⁹⁶⁶² is an apocalyptic number.

639662 is a deficient number, since it is larger than the sum of its proper divisors (319834).

639662 is a wasteful number, since it uses less digits than its factorization.

639662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319833.

The product of its digits is 11664, while the sum is 32.

The square root of 639662 is about 799.7887221010. The cubic root of 639662 is about 86.1622141189.

The spelling of 639662 in words is "six hundred thirty-nine thousand, six hundred sixty-two".