21612524265221 has 8 divisors (see below), whose sum is σ = 21727962077184. Its totient is φ = 21497359680160.

The previous prime is 21612524265161. The next prime is 21612524265229. The reversal of 21612524265221 is 12256242521612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21612524265221 is a prime.

It is a super-2 number, since 2×21612524265221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612524265229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68148101 + ... + 68464506.

It is an arithmetic number, because the mean of its divisors is an integer number (2715995259648).

Almost surely, 2^{21612524265221} is an apocalyptic number.

It is an amenable number.

21612524265221 is a deficient number, since it is larger than the sum of its proper divisors (115437811963).

21612524265221 is a wasteful number, since it uses less digits than its factorization.

21612524265221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136613451.

The product of its digits is 230400, while the sum is 41.

Adding to 21612524265221 its reverse (12256242521612), we get a palindrome (33868766786833).

The spelling of 21612524265221 in words is "twenty-one trillion, six hundred twelve billion, five hundred twenty-four million, two hundred sixty-five thousand, two hundred twenty-one".