644294338 has 16 divisors (see below), whose sum is σ = 973829376. Its totient is φ = 319690800.

The previous prime is 644294323. The next prime is 644294369. The reversal of 644294338 is 833492446.

It is a junction number, because it is equal to n+sod(n) for n = 644294294 and 644294303.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 329263 + ... + 331213.

It is an arithmetic number, because the mean of its divisors is an integer number (60864336).

Almost surely, 2^644294338 is an apocalyptic number.

644294338 is a deficient number, since it is larger than the sum of its proper divisors (329535038).

644294338 is a wasteful number, since it uses less digits than its factorization.

644294338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3129.

The product of its digits is 497664, while the sum is 43.

The square root of 644294338 is about 25382.9536894350. The cubic root of 644294338 is about 863.6970540337.

The spelling of 644294338 in words is "six hundred forty-four million, two hundred ninety-four thousand, three hundred thirty-eight".