21963613321 has 8 divisors (see below), whose sum is σ = 23793083720. Its totient is φ = 20274102576.

The previous prime is 21963613319. The next prime is 21963613379. The reversal of 21963613321 is 12331636912.

It can be written as a sum of positive squares in 4 ways, for example, as 10799366400 + 11164246921 = 103920^2 + 105661^2 .

It is not a de Polignac number, because 21963613321 - 2¹ = 21963613319 is a prime.

It is a super-2 number, since 2×21963613321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21963623321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4996350 + ... + 5000743.

It is an arithmetic number, because the mean of its divisors is an integer number (2974135465).

Almost surely, 2^21963613321 is an apocalyptic number.

It is an amenable number.

21963613321 is a deficient number, since it is larger than the sum of its proper divisors (1829470399).

21963613321 is an frugal number, since it uses more digits than its factorization.

21963613321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9997132 (or 9997106 counting only the distinct ones).

The product of its digits is 34992, while the sum is 37.

The spelling of 21963613321 in words is "twenty-one billion, nine hundred sixty-three million, six hundred thirteen thousand, three hundred twenty-one".