21615566213323 has 4 divisors (see below), whose sum is σ = 21710788972200. Its totient is φ = 21520343454448.

The previous prime is 21615566213273. The next prime is 21615566213357. The reversal of 21615566213323 is 32331266551612.

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 21615566213323 - 2¹⁷ = 21615566082251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21615566213023) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 47611379098 + ... + 47611379551.

It is an arithmetic number, because the mean of its divisors is an integer number (5427697243050).

Almost surely, 2^{21615566213323} is an apocalyptic number.

21615566213323 is a deficient number, since it is larger than the sum of its proper divisors (95222758877).

21615566213323 is an equidigital number, since it uses as much as digits as its factorization.

21615566213323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95222758876.

The product of its digits is 1166400, while the sum is 46.

The spelling of 21615566213323 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, two hundred thirteen thousand, three hundred twenty-three".