644361425 has 12 divisors (see below), whose sum is σ = 800294016. Its totient is φ = 514659600.

The previous prime is 644361413. The next prime is 644361461. The reversal of 644361425 is 524163446.

It is a de Polignac number, because none of the positive numbers 2^k-644361425 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 4649 + ... + 36198.

It is an arithmetic number, because the mean of its divisors is an integer number (66691168).

Almost surely, 2^644361425 is an apocalyptic number.

It is an amenable number.

644361425 is a deficient number, since it is larger than the sum of its proper divisors (155932591).

644361425 is a wasteful number, since it uses less digits than its factorization.

644361425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41488 (or 41483 counting only the distinct ones).

The product of its digits is 69120, while the sum is 35.

The square root of 644361425 is about 25384.2751521488. The cubic root of 644361425 is about 863.7270304124.

The spelling of 644361425 in words is "six hundred forty-four million, three hundred sixty-one thousand, four hundred twenty-five".