644340572 has 12 divisors (see below), whose sum is σ = 1133896680. Its totient is φ = 320370096.

The previous prime is 644340569. The next prime is 644340581. The reversal of 644340572 is 275043446.

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, 449243 + ... + 450674.

It is an arithmetic number, because the mean of its divisors is an integer number (94491390).

Almost surely, 2^644340572 is an apocalyptic number.

It is an amenable number.

644340572 is a deficient number, since it is larger than the sum of its proper divisors (489556108).

644340572 is a wasteful number, since it uses less digits than its factorization.

644340572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900100 (or 900098 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 35.

The square root of 644340572 is about 25383.8644024112. The cubic root of 644340572 is about 863.7177129221.

The spelling of 644340572 in words is "six hundred forty-four million, three hundred forty thousand, five hundred seventy-two".