645313408 has 32 divisors (see below), whose sum is σ = 1287042120. Its totient is φ = 322291200.

The previous prime is 645313399. The next prime is 645313433. The reversal of 645313408 is 804313546.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137338 + ... + 141958.

Almost surely, 2^645313408 is an apocalyptic number.

It is an amenable number.

645313408 is a deficient number, since it is larger than the sum of its proper divisors (641728712).

645313408 is a wasteful number, since it uses less digits than its factorization.

645313408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5726 (or 5714 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 645313408 is about 25403.0196630243. The cubic root of 645313408 is about 864.1521794131.

The spelling of 645313408 in words is "six hundred forty-five million, three hundred thirteen thousand, four hundred eight".