21209553223 has 2 divisors, whose sum is σ = 21209553224. Its totient is φ = 21209553222.

The previous prime is 21209553217. The next prime is 21209553283. The reversal of 21209553223 is 32235590212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21209553223 - 2⁵ = 21209553191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21209553283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10604776611 + 10604776612.

It is an arithmetic number, because the mean of its divisors is an integer number (10604776612).

Almost surely, 2^21209553223 is an apocalyptic number.

21209553223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21209553223 is an equidigital number, since it uses as much as digits as its factorization.

21209553223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 34.

The spelling of 21209553223 in words is "twenty-one billion, two hundred nine million, five hundred fifty-three thousand, two hundred twenty-three".