639171 has 20 divisors (see below), whose sum is σ = 1029952. Its totient is φ = 392688.

The previous prime is 639169. The next prime is 639181. The reversal of 639171 is 171936.

It is not a de Polignac number, because 639171 - 2¹ = 639169 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639151) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 750 + ... + 1356.

2⁶³⁹¹⁷¹ is an apocalyptic number.

639171 is a deficient number, since it is larger than the sum of its proper divisors (390781).

639171 is a wasteful number, since it uses less digits than its factorization.

639171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632 (or 623 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 639171 is about 799.4817071078. The cubic root of 639171 is about 86.1401626415.

The spelling of 639171 in words is "six hundred thirty-nine thousand, one hundred seventy-one".