644457050 has 24 divisors (see below), whose sum is σ = 1209697500. Its totient is φ = 255415680.

The previous prime is 644457049. The next prime is 644457061. The reversal of 644457050 is 50754446.

It can be written as a sum of positive squares in 6 ways, for example, as 197430601 + 447026449 = 14051^2 + 21143^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 644457050.

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, 53675 + ... + 64574.

Almost surely, 2^644457050 is an apocalyptic number.

644457050 is a deficient number, since it is larger than the sum of its proper divisors (565240450).

644457050 is a wasteful number, since it uses less digits than its factorization.

644457050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118370 (or 118365 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 35.

The square root of 644457050 is about 25386.1586302457. The cubic root of 644457050 is about 863.7697547845.

The spelling of 644457050 in words is "six hundred forty-four million, four hundred fifty-seven thousand, fifty".