644656562212 has 96 divisors (see below), whose sum is σ = 1324126137600. Its totient is φ = 271917015552.

The previous prime is 644656562197. The next prime is 644656562213. The reversal of 644656562212 is 212265656446.

It is a happy number.

It is a super-3 number, since 3×644656562212³ (a number of 36 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (644656562213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35032198 + ... + 35050594.

It is an arithmetic number, because the mean of its divisors is an integer number (13792980600).

Almost surely, 2^644656562212 is an apocalyptic number.

It is an amenable number.

644656562212 is an abundant number, since it is smaller than the sum of its proper divisors (679469575388).

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

644656562212 is a wasteful number, since it uses less digits than its factorization.

644656562212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19685 (or 19683 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 49.

The spelling of 644656562212 in words is "six hundred forty-four billion, six hundred fifty-six million, five hundred sixty-two thousand, two hundred twelve".