21223121315 has 64 divisors (see below), whose sum is σ = 30800563200. Its totient is φ = 13856832000.

The previous prime is 21223121233. The next prime is 21223121333. The reversal of 21223121315 is 51312132212.

It is not a de Polignac number, because 21223121315 - 2¹² = 21223117219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 2615765 + ... + 2623865.

It is an arithmetic number, because the mean of its divisors is an integer number (481258800).

Almost surely, 2^21223121315 is an apocalyptic number.

21223121315 is a deficient number, since it is larger than the sum of its proper divisors (9577441885).

21223121315 is a wasteful number, since it uses less digits than its factorization.

21223121315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8268.

The product of its digits is 720, while the sum is 23.

Adding to 21223121315 its reverse (51312132212), we get a palindrome (72535253527).

The spelling of 21223121315 in words is "twenty-one billion, two hundred twenty-three million, one hundred twenty-one thousand, three hundred fifteen".