21812115239 has 2 divisors, whose sum is σ = 21812115240. Its totient is φ = 21812115238.

The previous prime is 21812115233. The next prime is 21812115263. The reversal of 21812115239 is 93251121812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21812115239 - 2²⁸ = 21543679783 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21812115199 and 21812115208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21812115233) 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, 10906057619 + 10906057620.

It is an arithmetic number, because the mean of its divisors is an integer number (10906057620).

Almost surely, 2^21812115239 is an apocalyptic number.

21812115239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21812115239 is an equidigital number, since it uses as much as digits as its factorization.

21812115239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 35.

The spelling of 21812115239 in words is "twenty-one billion, eight hundred twelve million, one hundred fifteen thousand, two hundred thirty-nine".