21621402503231 has 16 divisors (see below), whose sum is σ = 22044059383680. Its totient is φ = 21199294871040.

The previous prime is 21621402503167. The next prime is 21621402503251. The reversal of 21621402503231 is 13230520412612.

It is not a de Polignac number, because 21621402503231 - 2⁶ = 21621402503167 is a prime.

It is a super-2 number, since 2×21621402503231² (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 (21621402503251) 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, 583728410 + ... + 583765448.

It is an arithmetic number, because the mean of its divisors is an integer number (1377753711480).

Almost surely, 2^{21621402503231} is an apocalyptic number.

21621402503231 is a deficient number, since it is larger than the sum of its proper divisors (422656880449).

21621402503231 is a wasteful number, since it uses less digits than its factorization.

21621402503231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44146.

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 21621402503231 its reverse (13230520412612), we get a palindrome (34851922915843).

The spelling of 21621402503231 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred two million, five hundred three thousand, two hundred thirty-one".