21113132231 has 2 divisors, whose sum is σ = 21113132232. Its totient is φ = 21113132230.

The previous prime is 21113132207. The next prime is 21113132239. The reversal of 21113132231 is 13223131112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113132231 is a prime.

It is a super-2 number, since 2×21113132231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113132239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556566115 + 10556566116.

It is an arithmetic number, because the mean of its divisors is an integer number (10556566116).

Almost surely, 2^21113132231 is an apocalyptic number.

21113132231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113132231 is an equidigital number, since it uses as much as digits as its factorization.

21113132231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

Adding to 21113132231 its reverse (13223131112), we get a palindrome (34336263343).

The spelling of 21113132231 in words is "twenty-one billion, one hundred thirteen million, one hundred thirty-two thousand, two hundred thirty-one".