21123321122131 has 2 divisors, whose sum is σ = 21123321122132. Its totient is φ = 21123321122130.

The previous prime is 21123321122021. The next prime is 21123321122191. The reversal of 21123321122131 is 13122112332112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21123321122131 - 2⁹ = 21123321121619 is a prime.

It is a super-2 number, since 2×21123321122131² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21123321122096 and 21123321122105.

It is not a weakly prime, because it can be changed into another prime (21123321122191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561660561065 + 10561660561066.

It is an arithmetic number, because the mean of its divisors is an integer number (10561660561066).

Almost surely, 2^{21123321122131} is an apocalyptic number.

21123321122131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123321122131 is an equidigital number, since it uses as much as digits as its factorization.

21123321122131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

Adding to 21123321122131 its reverse (13122112332112), we get a palindrome (34245433454243).

The spelling of 21123321122131 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred twenty-one million, one hundred twenty-two thousand, one hundred thirty-one".