21113131439 has 2 divisors, whose sum is σ = 21113131440. Its totient is φ = 21113131438.

The previous prime is 21113131421. The next prime is 21113131441. The reversal of 21113131439 is 93413131112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21113131439 - 2¹⁶ = 21113065903 is a prime.

Together with 21113131441, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113131469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556565719 + 10556565720.

It is an arithmetic number, because the mean of its divisors is an integer number (10556565720).

Almost surely, 2^21113131439 is an apocalyptic number.

21113131439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113131439 is an equidigital number, since it uses as much as digits as its factorization.

21113131439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The spelling of 21113131439 in words is "twenty-one billion, one hundred thirteen million, one hundred thirty-one thousand, four hundred thirty-nine".