644613460 has 24 divisors (see below), whose sum is σ = 1382492160. Its totient is φ = 252358944.

The previous prime is 644613451. The next prime is 644613461. The reversal of 644613460 is 64316446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644613461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341940 + ... + 343819.

It is an arithmetic number, because the mean of its divisors is an integer number (57603840).

Almost surely, 2^644613460 is an apocalyptic number.

It is an amenable number.

644613460 is an abundant number, since it is smaller than the sum of its proper divisors (737878700).

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

644613460 is a wasteful number, since it uses less digits than its factorization.

644613460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685815 (or 685813 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 644613460 is about 25389.2390590975. The cubic root of 644613460 is about 863.8396282276.

The spelling of 644613460 in words is "six hundred forty-four million, six hundred thirteen thousand, four hundred sixty".