321964321561 has 9 divisors (see below), whose sum is σ = 322830824799. Its totient is φ = 321100142424.

The previous prime is 321964321531. The next prime is 321964321633. The reversal of 321964321561 is 165123469123.

The square root of 321964321561 is 567419.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 271269097225 + 50695224336 = 520835^2 + 225156^2 .

It is not a de Polignac number, because 321964321561 - 2⁷ = 321964321433 is a prime.

It is a super-2 number, since 2×321964321561² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321964321531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 367119655 + ... + 367120531.

Almost surely, 2^321964321561 is an apocalyptic number.

321964321561 is the 567419-th square number.

321964321561 is the 283710-th centered octagonal number.

It is an amenable number.

321964321561 is a deficient number, since it is larger than the sum of its proper divisors (866503238).

321964321561 is an frugal number, since it uses more digits than its factorization.

321964321561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3048 (or 1524 counting only the distinct ones).

The product of its digits is 233280, while the sum is 43.

The spelling of 321964321561 in words is "three hundred twenty-one billion, nine hundred sixty-four million, three hundred twenty-one thousand, five hundred sixty-one".