21310321321 has 12 divisors (see below), whose sum is σ = 23813952372. Its totient is φ = 19001147904.

The previous prime is 21310321303. The next prime is 21310321349. The reversal of 21310321321 is 12312301312.

It can be written as a sum of positive squares in 2 ways, for example, as 14694288400 + 6616032921 = 121220^2 + 81339^2 .

It is not a de Polignac number, because 21310321321 - 2²⁹ = 20773450409 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21310321301) 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, 1730080 + ... + 1742353.

It is an arithmetic number, because the mean of its divisors is an integer number (1984496031).

Almost surely, 2^21310321321 is an apocalyptic number.

It is an amenable number.

21310321321 is a deficient number, since it is larger than the sum of its proper divisors (2503631051).

21310321321 is a wasteful number, since it uses less digits than its factorization.

21310321321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3472488 (or 3472469 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21310321321 its reverse (12312301312), we get a palindrome (33622622633).

The spelling of 21310321321 in words is "twenty-one billion, three hundred ten million, three hundred twenty-one thousand, three hundred twenty-one".