640308896 has 12 divisors (see below), whose sum is σ = 1260608202. Its totient is φ = 320154432.

The previous prime is 640308863. The next prime is 640308899. The reversal of 640308896 is 698803046.

It can be written as a sum of positive squares in only one way, i.e., 541027600 + 99281296 = 23260^2 + 9964^2 .

It is not an unprimeable number, because it can be changed into a prime (640308899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004795 + ... + 10004858.

Almost surely, 2^640308896 is an apocalyptic number.

It is an amenable number.

640308896 is a deficient number, since it is larger than the sum of its proper divisors (620299306).

640308896 is a wasteful number, since it uses less digits than its factorization.

640308896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20009663 (or 20009655 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 44.

The square root of 640308896 is about 25304.3256381197. The cubic root of 640308896 is about 861.9124987668.

The spelling of 640308896 in words is "six hundred forty million, three hundred eight thousand, eight hundred ninety-six".