644164212 has 12 divisors (see below), whose sum is σ = 1503049856. Its totient is φ = 214721400.

The previous prime is 644164189. The next prime is 644164217. The reversal of 644164212 is 212461446.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 644164212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644164217) 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, 26840164 + ... + 26840187.

Almost surely, 2^644164212 is an apocalyptic number.

It is an amenable number.

644164212 is an abundant number, since it is smaller than the sum of its proper divisors (858885644).

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

644164212 is a wasteful number, since it uses less digits than its factorization.

644164212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53680358 (or 53680356 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 644164212 is about 25380.3903043275. The cubic root of 644164212 is about 863.6389041047.

The spelling of 644164212 in words is "six hundred forty-four million, one hundred sixty-four thousand, two hundred twelve".