21534248539 has 2 divisors, whose sum is σ = 21534248540. Its totient is φ = 21534248538.

The previous prime is 21534248509. The next prime is 21534248563. The reversal of 21534248539 is 93584243512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21534248539 - 2⁵ = 21534248507 is a prime.

It is not a weakly prime, because it can be changed into another prime (21534248509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767124269 + 10767124270.

It is an arithmetic number, because the mean of its divisors is an integer number (10767124270).

Almost surely, 2^21534248539 is an apocalyptic number.

21534248539 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534248539 is an equidigital number, since it uses as much as digits as its factorization.

21534248539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1036800, while the sum is 46.

The spelling of 21534248539 in words is "twenty-one billion, five hundred thirty-four million, two hundred forty-eight thousand, five hundred thirty-nine".