21162535151321 has 4 divisors (see below), whose sum is σ = 21169840137012. Its totient is φ = 21155230165632.

The previous prime is 21162535151311. The next prime is 21162535151357. The reversal of 21162535151321 is 12315153526112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11827677061321 + 9334858090000 = 3439139^2 + 3055300^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162535151321 - 2²² = 21162530957017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21162535151311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3652488500 + ... + 3652494293.

It is an arithmetic number, because the mean of its divisors is an integer number (5292460034253).

Almost surely, 2^{21162535151321} is an apocalyptic number.

It is an amenable number.

21162535151321 is a deficient number, since it is larger than the sum of its proper divisors (7304985691).

21162535151321 is an equidigital number, since it uses as much as digits as its factorization.

21162535151321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7304985690.

The product of its digits is 54000, while the sum is 38.

Adding to 21162535151321 its reverse (12315153526112), we get a palindrome (33477688677433).

The spelling of 21162535151321 in words is "twenty-one trillion, one hundred sixty-two billion, five hundred thirty-five million, one hundred fifty-one thousand, three hundred twenty-one".