21322311515 has 4 divisors (see below), whose sum is σ = 25586773824. Its totient is φ = 17057849208.

The previous prime is 21322311497. The next prime is 21322311553. The reversal of 21322311515 is 51511322312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21322311515 - 2²⁰ = 21321262939 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2132231147 + ... + 2132231156.

It is an arithmetic number, because the mean of its divisors is an integer number (6396693456).

Almost surely, 2^21322311515 is an apocalyptic number.

21322311515 is a deficient number, since it is larger than the sum of its proper divisors (4264462309).

21322311515 is an equidigital number, since it uses as much as digits as its factorization.

21322311515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4264462308.

The product of its digits is 1800, while the sum is 26.

Adding to 21322311515 its reverse (51511322312), we get a palindrome (72833633827).

The spelling of 21322311515 in words is "twenty-one billion, three hundred twenty-two million, three hundred eleven thousand, five hundred fifteen".