640392480 has 576 divisors, whose sum is σ = 2804675328. Its totient is φ = 134369280.

The previous prime is 640392461. The next prime is 640392497. The reversal of 640392480 is 84293046.

It is a happy number.

640392480 is a `hidden beast` number, since 6 + 403 + 9 + 248 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3537990 + ... + 3538170.

It is an arithmetic number, because the mean of its divisors is an integer number (4869228).

Almost surely, 2^640392480 is an apocalyptic number.

640392480 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 640392480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1402337664).

640392480 is an abundant number, since it is smaller than the sum of its proper divisors (2164282848).

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

640392480 is a wasteful number, since it uses less digits than its factorization.

640392480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 640392480 is about 25305.9771595566. The cubic root of 640392480 is about 861.9500009579.

The spelling of 640392480 in words is "six hundred forty million, three hundred ninety-two thousand, four hundred eighty".