21231311879 has 2 divisors, whose sum is σ = 21231311880. Its totient is φ = 21231311878.

The previous prime is 21231311869. The next prime is 21231311903. The reversal of 21231311879 is 97811313212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231311879 - 2²⁸ = 20962876423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231311819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615655939 + 10615655940.

It is an arithmetic number, because the mean of its divisors is an integer number (10615655940).

Almost surely, 2^21231311879 is an apocalyptic number.

21231311879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231311879 is an equidigital number, since it uses as much as digits as its factorization.

21231311879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The spelling of 21231311879 in words is "twenty-one billion, two hundred thirty-one million, three hundred eleven thousand, eight hundred seventy-nine".