640722332 has 24 divisors (see below), whose sum is σ = 1181115600. Its totient is φ = 303284736.

The previous prime is 640722323. The next prime is 640722343. The reversal of 640722332 is 233227046.

It is a junction number, because it is equal to n+sod(n) for n = 640722295 and 640722304.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 170894 + ... + 174602.

It is an arithmetic number, because the mean of its divisors is an integer number (49213150).

Almost surely, 2^640722332 is an apocalyptic number.

It is an amenable number.

640722332 is a deficient number, since it is larger than the sum of its proper divisors (540393268).

640722332 is a wasteful number, since it uses less digits than its factorization.

640722332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6005 (or 6003 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 29.

The square root of 640722332 is about 25312.4935950609. The cubic root of 640722332 is about 862.0979660156.

Adding to 640722332 its reverse (233227046), we get a palindrome (873949378).

The spelling of 640722332 in words is "six hundred forty million, seven hundred twenty-two thousand, three hundred thirty-two".