21043532459 has 2 divisors, whose sum is σ = 21043532460. Its totient is φ = 21043532458.

The previous prime is 21043532443. The next prime is 21043532513. The reversal of 21043532459 is 95423534012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21043532459 - 2⁴ = 21043532443 is a prime.

It is not a weakly prime, because it can be changed into another prime (21043532359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521766229 + 10521766230.

It is an arithmetic number, because the mean of its divisors is an integer number (10521766230).

Almost surely, 2^21043532459 is an apocalyptic number.

21043532459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043532459 is an equidigital number, since it uses as much as digits as its factorization.

21043532459 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 38.

The spelling of 21043532459 in words is "twenty-one billion, forty-three million, five hundred thirty-two thousand, four hundred fifty-nine".