21131002213 has 2 divisors, whose sum is σ = 21131002214. Its totient is φ = 21131002212.

The previous prime is 21131002169. The next prime is 21131002219. The reversal of 21131002213 is 31220013112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20768556769 + 362445444 = 144113^2 + 19038^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131002213 - 2²⁹ = 20594131301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21131002219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565501106 + 10565501107.

It is an arithmetic number, because the mean of its divisors is an integer number (10565501107).

Almost surely, 2^21131002213 is an apocalyptic number.

It is an amenable number.

21131002213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131002213 is an equidigital number, since it uses as much as digits as its factorization.

21131002213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21131002213 its reverse (31220013112), we get a palindrome (52351015325).

The spelling of 21131002213 in words is "twenty-one billion, one hundred thirty-one million, two thousand, two hundred thirteen".