21560800823 has 2 divisors, whose sum is σ = 21560800824. Its totient is φ = 21560800822.

The previous prime is 21560800721. The next prime is 21560800841. The reversal of 21560800823 is 32800806512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21560800823 - 2³² = 17265833527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21560800873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10780400411 + 10780400412.

It is an arithmetic number, because the mean of its divisors is an integer number (10780400412).

Almost surely, 2^21560800823 is an apocalyptic number.

21560800823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21560800823 is an equidigital number, since it uses as much as digits as its factorization.

21560800823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 35.

The spelling of 21560800823 in words is "twenty-one billion, five hundred sixty million, eight hundred thousand, eight hundred twenty-three".