644219416 has 16 divisors (see below), whose sum is σ = 1208188440. Its totient is φ = 322035840.

The previous prime is 644219341. The next prime is 644219431. The reversal of 644219416 is 614912446.

It is a congruent number.

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, 50751 + ... + 62161.

Almost surely, 2^644219416 is an apocalyptic number.

It is an amenable number.

644219416 is a deficient number, since it is larger than the sum of its proper divisors (563969024).

644219416 is a wasteful number, since it uses less digits than its factorization.

644219416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18474 (or 18470 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 644219416 is about 25381.4778135553. The cubic root of 644219416 is about 863.6635742945.

It can be divided in two parts, 64421 and 9416, that added together give a palindrome (73837).

The spelling of 644219416 in words is "six hundred forty-four million, two hundred nineteen thousand, four hundred sixteen".