640524330 has 48 divisors (see below), whose sum is σ = 1680667560. Its totient is φ = 169236864.

The previous prime is 640524323. The next prime is 640524377. The reversal of 640524330 is 33425046.

It can be written as a sum of positive squares in 4 ways, for example, as 568393281 + 72131049 = 23841^2 + 8493^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 640524294 and 640524303.

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, 22837 + ... + 42456.

Almost surely, 2^640524330 is an apocalyptic number.

640524330 is an abundant number, since it is smaller than the sum of its proper divisors (1040143230).

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

640524330 is a wasteful number, since it uses less digits than its factorization.

640524330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65415 (or 65412 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

The square root of 640524330 is about 25308.5821412421. The cubic root of 640524330 is about 862.0091523442.

Adding to 640524330 its reverse (33425046), we get a palindrome (673949376).

The spelling of 640524330 in words is "six hundred forty million, five hundred twenty-four thousand, three hundred thirty".