639918552 has 128 divisors (see below), whose sum is σ = 2022451200. Its totient is φ = 164187648.

The previous prime is 639918547. The next prime is 639918557. The reversal of 639918552 is 255819936.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (639918547) and next prime (639918557).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639918557) 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, 76849 + ... + 84767.

It is an arithmetic number, because the mean of its divisors is an integer number (15800400).

Almost surely, 2^639918552 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 639918552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1011225600).

639918552 is an abundant number, since it is smaller than the sum of its proper divisors (1382532648).

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

639918552 is a wasteful number, since it uses less digits than its factorization.

639918552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7985 (or 7981 counting only the distinct ones).

The product of its digits is 583200, while the sum is 48.

The square root of 639918552 is about 25296.6114726854. The cubic root of 639918552 is about 861.7373172959.

The spelling of 639918552 in words is "six hundred thirty-nine million, nine hundred eighteen thousand, five hundred fifty-two".