644548216 has 32 divisors (see below), whose sum is σ = 1303520400. Its totient is φ = 297020160.

The previous prime is 644548189. The next prime is 644548231. The reversal of 644548216 is 612845446.

It is a congruent number.

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, 67380 + ... + 76348.

Almost surely, 2^644548216 is an apocalyptic number.

It is an amenable number.

644548216 is an abundant number, since it is smaller than the sum of its proper divisors (658972184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644548216 is a wasteful number, since it uses less digits than its factorization.

644548216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9679 (or 9675 counting only the distinct ones).

The product of its digits is 184320, while the sum is 40.

The square root of 644548216 is about 25387.9541515263. The cubic root of 644548216 is about 863.8104829813.

The spelling of 644548216 in words is "six hundred forty-four million, five hundred forty-eight thousand, two hundred sixteen".