326561221613664 has 144 divisors (see below), whose sum is σ = 944853565690944. Its totient is φ = 106966419609600.

The previous prime is 326561221613663. The next prime is 326561221613689. The reversal of 326561221613664 is 466316122165623.

326561221613664 is a `hidden beast` number, since 3 + 2 + 6 + 5 + 6 + 12 + 2 + 1 + 613 + 6 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a self number, because there is not a number n which added to its sum of digits gives 326561221613664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (326561221613663) 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 23 ways as a sum of consecutive naturals, for example, 22960767 + ... + 34355774.

It is an arithmetic number, because the mean of its divisors is an integer number (6561483095076).

Almost surely, 2^{326561221613664} is an apocalyptic number.

It is an amenable number.

326561221613664 is an abundant number, since it is smaller than the sum of its proper divisors (618292344077280).

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

326561221613664 is a wasteful number, since it uses less digits than its factorization.

326561221613664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57316901 (or 57316890 counting only the distinct ones).

The product of its digits is 11197440, while the sum is 54.

The spelling of 326561221613664 in words is "three hundred twenty-six trillion, five hundred sixty-one billion, two hundred twenty-one million, six hundred thirteen thousand, six hundred sixty-four".