644025452 has 12 divisors (see below), whose sum is σ = 1288050960. Its totient is φ = 276010896.

The previous prime is 644025439. The next prime is 644025457. The reversal of 644025452 is 254520446.

644025452 is an admirable number.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (644025457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11500427 + ... + 11500482.

It is an arithmetic number, because the mean of its divisors is an integer number (107337580).

Almost surely, 2^644025452 is an apocalyptic number.

It is an amenable number.

644025452 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

644025452 is a wasteful number, since it uses less digits than its factorization.

644025452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23000920 (or 23000918 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 32.

The square root of 644025452 is about 25377.6565505958. The cubic root of 644025452 is about 863.5768872369.

Adding to 644025452 its reverse (254520446), we get a palindrome (898545898).

The spelling of 644025452 in words is "six hundred forty-four million, twenty-five thousand, four hundred fifty-two".