644570438 has 8 divisors (see below), whose sum is σ = 966973080. Its totient is φ = 322246080.

The previous prime is 644570431. The next prime is 644570449. The reversal of 644570438 is 834075446.

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

It is a junction number, because it is equal to n+sod(n) for n = 644570395 and 644570404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644570431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9878 + ... + 37238.

It is an arithmetic number, because the mean of its divisors is an integer number (120871635).

Almost surely, 2^644570438 is an apocalyptic number.

644570438 is a deficient number, since it is larger than the sum of its proper divisors (322402642).

644570438 is a wasteful number, since it uses less digits than its factorization.

644570438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39142.

The product of its (nonzero) digits is 322560, while the sum is 41.

The square root of 644570438 is about 25388.3917962521. The cubic root of 644570438 is about 863.8204100255.

The spelling of 644570438 in words is "six hundred forty-four million, five hundred seventy thousand, four hundred thirty-eight".