21544212713 has 2 divisors, whose sum is σ = 21544212714. Its totient is φ = 21544212712.

The previous prime is 21544212667. The next prime is 21544212721. The reversal of 21544212713 is 31721244512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17307244249 + 4236968464 = 131557^2 + 65092^2 .

It is a cyclic number.

It is not a de Polignac number, because 21544212713 - 2⁶ = 21544212649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21544212713.

It is not a weakly prime, because it can be changed into another prime (21544212763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772106356 + 10772106357.

It is an arithmetic number, because the mean of its divisors is an integer number (10772106357).

Almost surely, 2^21544212713 is an apocalyptic number.

It is an amenable number.

21544212713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21544212713 is an equidigital number, since it uses as much as digits as its factorization.

21544212713 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 32.

The spelling of 21544212713 in words is "twenty-one billion, five hundred forty-four million, two hundred twelve thousand, seven hundred thirteen".