644022472 has 16 divisors (see below), whose sum is σ = 1213801740. Its totient is φ = 320342016.

The previous prime is 644022433. The next prime is 644022473. The reversal of 644022472 is 274220446.

It can be written as a sum of positive squares in 2 ways, for example, as 642419716 + 1602756 = 25346^2 + 1266^2 .

It is not an unprimeable number, because it can be changed into a prime (644022473) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207013 + ... + 210100.

Almost surely, 2^644022472 is an apocalyptic number.

It is an amenable number.

644022472 is a deficient number, since it is larger than the sum of its proper divisors (569779268).

644022472 is a wasteful number, since it uses less digits than its factorization.

644022472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417312 (or 417308 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 31.

The square root of 644022472 is about 25377.5978374629. The cubic root of 644022472 is about 863.5755552693.

The spelling of 644022472 in words is "six hundred forty-four million, twenty-two thousand, four hundred seventy-two".