639999360 has 1024 divisors, whose sum is σ = 3125606400. Its totient is φ = 119439360.

The previous prime is 639999331. The next prime is 639999377. The reversal of 639999360 is 63999936.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 639999297 and 639999306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 17297262 + ... + 17297298.

It is an arithmetic number, because the mean of its divisors is an integer number (3052350).

Almost surely, 2^639999360 is an apocalyptic number.

639999360 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639999360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1562803200).

639999360 is an abundant number, since it is smaller than the sum of its proper divisors (2485607040).

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

639999360 is a wasteful number, since it uses less digits than its factorization.

639999360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 2125764, while the sum is 54.

The square root of 639999360 is about 25298.2086322332. The cubic root of 639999360 is about 861.7735887547.

It can be divided in two parts, 639 and 999360, that added together give a palindrome (999999).

The spelling of 639999360 in words is "six hundred thirty-nine million, nine hundred ninety-nine thousand, three hundred sixty".