21365265352439 has 2 divisors, whose sum is σ = 21365265352440. Its totient is φ = 21365265352438.

The previous prime is 21365265352427. The next prime is 21365265352511. The reversal of 21365265352439 is 93425356256312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21365265352439 - 2⁴ = 21365265352423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21365265322439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682632676219 + 10682632676220.

It is an arithmetic number, because the mean of its divisors is an integer number (10682632676220).

Almost surely, 2^{21365265352439} is an apocalyptic number.

21365265352439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365265352439 is an equidigital number, since it uses as much as digits as its factorization.

21365265352439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992000, while the sum is 56.

The spelling of 21365265352439 in words is "twenty-one trillion, three hundred sixty-five billion, two hundred sixty-five million, three hundred fifty-two thousand, four hundred thirty-nine".