644201925 has 12 divisors (see below), whose sum is σ = 1065080640. Its totient is φ = 343574320.

The previous prime is 644201923. The next prime is 644201933. The reversal of 644201925 is 529102446.

It is not a de Polignac number, because 644201925 - 2¹ = 644201923 is a prime.

It is a super-2 number, since 2×644201925² = 829992240347411250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644201923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4294605 + ... + 4294754.

It is an arithmetic number, because the mean of its divisors is an integer number (88756720).

Almost surely, 2^644201925 is an apocalyptic number.

It is an amenable number.

644201925 is a deficient number, since it is larger than the sum of its proper divisors (420878715).

644201925 is a wasteful number, since it uses less digits than its factorization.

644201925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8589372 (or 8589367 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 644201925 is about 25381.1332489312. The cubic root of 644201925 is about 863.6557578705.

The spelling of 644201925 in words is "six hundred forty-four million, two hundred one thousand, nine hundred twenty-five".