644950675 has 12 divisors (see below), whose sum is σ = 846782856. Its totient is φ = 485609600.

The previous prime is 644950661. The next prime is 644950681. The reversal of 644950675 is 576059446.

It is not a de Polignac number, because 644950675 - 2¹⁷ = 644819603 is a prime.

It is a super-2 number, since 2×644950675² = 831922746365911250, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 758341 + ... + 759190.

It is an arithmetic number, because the mean of its divisors is an integer number (70565238).

Almost surely, 2^644950675 is an apocalyptic number.

644950675 is a deficient number, since it is larger than the sum of its proper divisors (201832181).

644950675 is a wasteful number, since it uses less digits than its factorization.

644950675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1517558 (or 1517553 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The square root of 644950675 is about 25395.8790948453. The cubic root of 644950675 is about 863.9902347112.

The spelling of 644950675 in words is "six hundred forty-four million, nine hundred fifty thousand, six hundred seventy-five".