21231243311 has 2 divisors, whose sum is σ = 21231243312. Its totient is φ = 21231243310.

The previous prime is 21231243301. The next prime is 21231243329. The reversal of 21231243311 is 11334213212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231243311 - 2²² = 21227049007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231243301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615621655 + 10615621656.

It is an arithmetic number, because the mean of its divisors is an integer number (10615621656).

Almost surely, 2^21231243311 is an apocalyptic number.

21231243311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231243311 is an equidigital number, since it uses as much as digits as its factorization.

21231243311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 23.

Adding to 21231243311 its reverse (11334213212), we get a palindrome (32565456523).

The spelling of 21231243311 in words is "twenty-one billion, two hundred thirty-one million, two hundred forty-three thousand, three hundred eleven".