644924451222 has 20 divisors (see below), whose sum is σ = 1445108492916. Its totient is φ = 214974817020.

The previous prime is 644924451221. The next prime is 644924451239. The reversal of 644924451222 is 222154429446.

644924451222 is a `hidden beast` number, since 6 + 4 + 4 + 92 + 44 + 512 + 2 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644924451221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1990507404 + ... + 1990507727.

Almost surely, 2^644924451222 is an apocalyptic number.

644924451222 is an abundant number, since it is smaller than the sum of its proper divisors (800184041694).

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

644924451222 is a wasteful number, since it uses less digits than its factorization.

644924451222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3981015145 (or 3981015136 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 45.

The spelling of 644924451222 in words is "six hundred forty-four billion, nine hundred twenty-four million, four hundred fifty-one thousand, two hundred twenty-two".