639924480 has 216 divisors, whose sum is σ = 2384943288. Its totient is φ = 157483008.

The previous prime is 639924457. The next prime is 639924517. The reversal of 639924480 is 84429936.

639924480 is a `hidden beast` number, since 63 + 99 + 24 + 480 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 36864 + 639887616 = 192^2 + 25296^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 147624 + ... + 151896.

Almost surely, 2^639924480 is an apocalyptic number.

639924480 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 639924480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1192471644).

639924480 is an abundant number, since it is smaller than the sum of its proper divisors (1745018808).

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

639924480 is a wasteful number, since it uses less digits than its factorization.

639924480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4313 (or 4296 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 639924480 is about 25296.7286422573. The cubic root of 639924480 is about 861.7399782403.

The spelling of 639924480 in words is "six hundred thirty-nine million, nine hundred twenty-four thousand, four hundred eighty".