639252822 has 64 divisors (see below), whose sum is σ = 1410877440. Its totient is φ = 191877504.

The previous prime is 639252793. The next prime is 639252827. The reversal of 639252822 is 228252936.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639252827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 987703 + ... + 988349.

It is an arithmetic number, because the mean of its divisors is an integer number (22044960).

Almost surely, 2^639252822 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639252822, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (705438720).

639252822 is an abundant number, since it is smaller than the sum of its proper divisors (771624618).

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

639252822 is a wasteful number, since it uses less digits than its factorization.

639252822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957.

The product of its digits is 103680, while the sum is 39.

The square root of 639252822 is about 25283.4495668609. The cubic root of 639252822 is about 861.4383816272.

The spelling of 639252822 in words is "six hundred thirty-nine million, two hundred fifty-two thousand, eight hundred twenty-two".