644736125 has 16 divisors (see below), whose sum is σ = 877780800. Its totient is φ = 468898000.

The previous prime is 644736121. The next prime is 644736151. The reversal of 644736125 is 521637446.

It is a happy number.

It is not a de Polignac number, because 644736125 - 2² = 644736121 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644736121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233075 + ... + 235824.

It is an arithmetic number, because the mean of its divisors is an integer number (54861300).

Almost surely, 2^644736125 is an apocalyptic number.

It is an amenable number.

644736125 is a deficient number, since it is larger than the sum of its proper divisors (233044675).

644736125 is a wasteful number, since it uses less digits than its factorization.

644736125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468925 (or 468915 counting only the distinct ones).

The product of its digits is 120960, while the sum is 38.

The square root of 644736125 is about 25391.6546329695. The cubic root of 644736125 is about 863.8944187721.

The spelling of 644736125 in words is "six hundred forty-four million, seven hundred thirty-six thousand, one hundred twenty-five".