21021112613 has 2 divisors, whose sum is σ = 21021112614. Its totient is φ = 21021112612.

The previous prime is 21021112589. The next prime is 21021112621. The reversal of 21021112613 is 31621112012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20191557409 + 829555204 = 142097^2 + 28802^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021112613 - 2¹⁰ = 21021111589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021112633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510556306 + 10510556307.

It is an arithmetic number, because the mean of its divisors is an integer number (10510556307).

Almost surely, 2^21021112613 is an apocalyptic number.

It is an amenable number.

21021112613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021112613 is an equidigital number, since it uses as much as digits as its factorization.

21021112613 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 21021112613 its reverse (31621112012), we get a palindrome (52642224625).

The spelling of 21021112613 in words is "twenty-one billion, twenty-one million, one hundred twelve thousand, six hundred thirteen".