644151224664 has 48 divisors (see below), whose sum is σ = 1744613956800. Its totient is φ = 214712432064.

The previous prime is 644151224663. The next prime is 644151224681. The reversal of 644151224664 is 466422151446.

644151224664 is a `hidden beast` number, since 6 + 4 + 415 + 1 + 224 + 6 + 6 + 4 = 666.

It is a super-2 number, since 2×644151224664² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644151224663) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5449017 + ... + 5565975.

It is an arithmetic number, because the mean of its divisors is an integer number (36346124100).

Almost surely, 2^644151224664 is an apocalyptic number.

It is an amenable number.

644151224664 is an abundant number, since it is smaller than the sum of its proper divisors (1100462732136).

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

644151224664 is a wasteful number, since it uses less digits than its factorization.

644151224664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193464 (or 193457 counting only the distinct ones).

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

The spelling of 644151224664 in words is "six hundred forty-four billion, one hundred fifty-one million, two hundred twenty-four thousand, six hundred sixty-four".