21303508433 has 2 divisors, whose sum is σ = 21303508434. Its totient is φ = 21303508432.

The previous prime is 21303508427. The next prime is 21303508451. The reversal of 21303508433 is 33480530312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20355299584 + 948208849 = 142672^2 + 30793^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303508433 - 2²² = 21299314129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21303508433.

It is not a weakly prime, because it can be changed into another prime (21303508403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651754216 + 10651754217.

It is an arithmetic number, because the mean of its divisors is an integer number (10651754217).

Almost surely, 2^21303508433 is an apocalyptic number.

It is an amenable number.

21303508433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303508433 is an equidigital number, since it uses as much as digits as its factorization.

21303508433 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 32.

The spelling of 21303508433 in words is "twenty-one billion, three hundred three million, five hundred eight thousand, four hundred thirty-three".