21612562422321 has 16 divisors (see below), whose sum is σ = 32858918434944. Its totient is φ = 12517683212544.

The previous prime is 21612562422313. The next prime is 21612562422371. The reversal of 21612562422321 is 12322426521612.

It is not a de Polignac number, because 21612562422321 - 2³ = 21612562422313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 21612562422321.

It is not an unprimeable number, because it can be changed into a prime (21612562422371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16299066021 + ... + 16299067346.

It is an arithmetic number, because the mean of its divisors is an integer number (2053682402184).

Almost surely, 2^{21612562422321} is an apocalyptic number.

It is an amenable number.

21612562422321 is a deficient number, since it is larger than the sum of its proper divisors (11246356012623).

21612562422321 is a wasteful number, since it uses less digits than its factorization.

21612562422321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32598133400.

The product of its digits is 138240, while the sum is 39.

Adding to 21612562422321 its reverse (12322426521612), we get a palindrome (33934988943933).

The spelling of 21612562422321 in words is "twenty-one trillion, six hundred twelve billion, five hundred sixty-two million, four hundred twenty-two thousand, three hundred twenty-one".