639342144 has 84 divisors (see below), whose sum is σ = 2094366144. Its totient is φ = 182668032.

The previous prime is 639342139. The next prime is 639342157. The reversal of 639342144 is 441243936.

It is a happy number.

639342144 is a `hidden beast` number, since 639 + 3 + 4 + 2 + 14 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (84).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 639342099 and 639342108.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75252 + ... + 83315.

Almost surely, 2^639342144 is an apocalyptic number.

639342144 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

639342144 is an abundant number, since it is smaller than the sum of its proper divisors (1455024000).

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

639342144 is a wasteful number, since it uses less digits than its factorization.

639342144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158592 (or 158579 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 639342144 is about 25285.2159176069. The cubic root of 639342144 is about 861.4785023290.

The spelling of 639342144 in words is "six hundred thirty-nine million, three hundred forty-two thousand, one hundred forty-four".