644446634 has 8 divisors (see below), whose sum is σ = 1041029220. Its totient is φ = 297436896.

The previous prime is 644446609. The next prime is 644446661. The reversal of 644446634 is 436644446.

It can be written as a sum of positive squares in 2 ways, for example, as 639837025 + 4609609 = 25295^2 + 2147^2 .

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

It is a super-2 number, since 2×644446634² = 830622928147859912, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644446591 and 644446600.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12393179 + ... + 12393230.

Almost surely, 2^644446634 is an apocalyptic number.

644446634 is a deficient number, since it is larger than the sum of its proper divisors (396582586).

644446634 is a wasteful number, since it uses less digits than its factorization.

644446634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24786424.

The product of its digits is 663552, while the sum is 41.

The square root of 644446634 is about 25385.9534782525. The cubic root of 644446634 is about 863.7651012165.

The spelling of 644446634 in words is "six hundred forty-four million, four hundred forty-six thousand, six hundred thirty-four".