21243524413 has 2 divisors, whose sum is σ = 21243524414. Its totient is φ = 21243524412.

The previous prime is 21243524369. The next prime is 21243524417. The reversal of 21243524413 is 31442534212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20181611844 + 1061912569 = 142062^2 + 32587^2 .

It is a cyclic number.

It is not a de Polignac number, because 21243524413 - 2²⁹ = 20706653501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21243524417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621762206 + 10621762207.

It is an arithmetic number, because the mean of its divisors is an integer number (10621762207).

Almost surely, 2^21243524413 is an apocalyptic number.

It is an amenable number.

21243524413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21243524413 is an equidigital number, since it uses as much as digits as its factorization.

21243524413 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 31.

The spelling of 21243524413 in words is "twenty-one billion, two hundred forty-three million, five hundred twenty-four thousand, four hundred thirteen".