639492 has 48 divisors (see below), whose sum is σ = 1784832. Its totient is φ = 174240.

The previous prime is 639491. The next prime is 639493. The reversal of 639492 is 294936.

It is an interprime number because it is at equal distance from previous prime (639491) and next prime (639493).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639492.

It is not an unprimeable number, because it can be changed into a prime (639491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1767 + ... + 2097.

It is an arithmetic number, because the mean of its divisors is an integer number (37184).

2⁶³⁹⁴⁹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (892416).

639492 is an abundant number, since it is smaller than the sum of its proper divisors (1145340).

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

639492 is a wasteful number, since it uses less digits than its factorization.

639492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 366 counting only the distinct ones).

The product of its digits is 11664, while the sum is 33.

The square root of 639492 is about 799.6824369711. The cubic root of 639492 is about 86.1545804654.

Adding to 639492 its product of digits (11664), we get a palindrome (651156).

The spelling of 639492 in words is "six hundred thirty-nine thousand, four hundred ninety-two".