644710370 has 8 divisors (see below), whose sum is σ = 1160478684. Its totient is φ = 257884144.

The previous prime is 644710361. The next prime is 644710433. The reversal of 644710370 is 73017446.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 639230089 + 5480281 = 25283^2 + 2341^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×644710370² = 831302922371073800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32235509 + ... + 32235528.

Almost surely, 2^644710370 is an apocalyptic number.

644710370 is a deficient number, since it is larger than the sum of its proper divisors (515768314).

644710370 is a wasteful number, since it uses less digits than its factorization.

644710370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64471044.

The product of its (nonzero) digits is 14112, while the sum is 32.

The square root of 644710370 is about 25391.1474730860. The cubic root of 644710370 is about 863.8829154112.

The spelling of 644710370 in words is "six hundred forty-four million, seven hundred ten thousand, three hundred seventy".