21321326345 has 16 divisors (see below), whose sum is σ = 28067497920. Its totient is φ = 15419784000.

The previous prime is 21321326333. The next prime is 21321326399. The reversal of 21321326345 is 54362312312.

It is not a de Polignac number, because 21321326345 - 2⁶ = 21321326281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1073006 + ... + 1092695.

It is an arithmetic number, because the mean of its divisors is an integer number (1754218620).

Almost surely, 2^21321326345 is an apocalyptic number.

It is an amenable number.

21321326345 is a deficient number, since it is larger than the sum of its proper divisors (6746171575).

21321326345 is a wasteful number, since it uses less digits than its factorization.

21321326345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165896.

The product of its digits is 25920, while the sum is 32.

Adding to 21321326345 its reverse (54362312312), we get a palindrome (75683638657).

The spelling of 21321326345 in words is "twenty-one billion, three hundred twenty-one million, three hundred twenty-six thousand, three hundred forty-five".