640045328 has 40 divisors (see below), whose sum is σ = 1338044568. Its totient is φ = 294838272.

The previous prime is 640045297. The next prime is 640045363. The reversal of 640045328 is 823540046.

It can be written as a sum of positive squares in 4 ways, for example, as 401281024 + 238764304 = 20032^2 + 15452^2 .

It is a junction number, because it is equal to n+sod(n) for n = 640045294 and 640045303.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117350 + ... + 122682.

Almost surely, 2^640045328 is an apocalyptic number.

It is an amenable number.

640045328 is an abundant number, since it is smaller than the sum of its proper divisors (697999240).

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

640045328 is a wasteful number, since it uses less digits than its factorization.

640045328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5931 (or 5925 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 640045328 is about 25299.1171387462. The cubic root of 640045328 is about 861.7942205774.

The spelling of 640045328 in words is "six hundred forty million, forty-five thousand, three hundred twenty-eight".