21013131102221 has 2 divisors, whose sum is σ = 21013131102222. Its totient is φ = 21013131102220.

The previous prime is 21013131102179. The next prime is 21013131102247. The reversal of 21013131102221 is 12220113131012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19108386086596 + 1904745015625 = 4371314^2 + 1380125^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013131102221 - 2²⁶ = 21013063993357 is a prime.

It is a super-2 number, since 2×21013131102221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21013131102193 and 21013131102202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013191102221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506565551110 + 10506565551111.

It is an arithmetic number, because the mean of its divisors is an integer number (10506565551111).

Almost surely, 2^{21013131102221} is an apocalyptic number.

It is an amenable number.

21013131102221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013131102221 is an equidigital number, since it uses as much as digits as its factorization.

21013131102221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 21013131102221 its reverse (12220113131012), we get a palindrome (33233244233233).

The spelling of 21013131102221 in words is "twenty-one trillion, thirteen billion, one hundred thirty-one million, one hundred two thousand, two hundred twenty-one".