644072212 has 24 divisors (see below), whose sum is σ = 1288681856. Its totient is φ = 275915808.

The previous prime is 644072179. The next prime is 644072237. The reversal of 644072212 is 212270446.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128098 + ... + 133030.

Almost surely, 2^644072212 is an apocalyptic number.

It is an amenable number.

644072212 is an abundant number, since it is smaller than the sum of its proper divisors (644609644).

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

644072212 is a wasteful number, since it uses less digits than its factorization.

644072212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9607 (or 9605 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 644072212 is about 25378.5778167335. The cubic root of 644072212 is about 863.5977869689.

The spelling of 644072212 in words is "six hundred forty-four million, seventy-two thousand, two hundred twelve".