21111535531213 has 2 divisors, whose sum is σ = 21111535531214. Its totient is φ = 21111535531212.

The previous prime is 21111535531181. The next prime is 21111535531253. The reversal of 21111535531213 is 31213553511112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19253815598889 + 1857719932324 = 4387917^2 + 1362982^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111535531213 - 2⁵ = 21111535531181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111535531253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555767765606 + 10555767765607.

It is an arithmetic number, because the mean of its divisors is an integer number (10555767765607).

Almost surely, 2^{21111535531213} is an apocalyptic number.

It is an amenable number.

21111535531213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111535531213 is an equidigital number, since it uses as much as digits as its factorization.

21111535531213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13500, while the sum is 34.

The spelling of 21111535531213 in words is "twenty-one trillion, one hundred eleven billion, five hundred thirty-five million, five hundred thirty-one thousand, two hundred thirteen".