639168 has 28 divisors (see below), whose sum is σ = 1691640. Its totient is φ = 212992.

The previous prime is 639167. The next prime is 639169. The reversal of 639168 is 861936.

It is an interprime number because it is at equal distance from previous prime (639167) and next prime (639169).

It is not an unprimeable number, because it can be changed into a prime (639167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1473 + ... + 1856.

2⁶³⁹¹⁶⁸ is an apocalyptic number.

It is an amenable number.

639168 is an abundant number, since it is smaller than the sum of its proper divisors (1052472).

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

639168 is a wasteful number, since it uses less digits than its factorization.

639168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3344 (or 3334 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 639168 is about 799.4798308901. The cubic root of 639168 is about 86.1400278728.

The spelling of 639168 in words is "six hundred thirty-nine thousand, one hundred sixty-eight".