21333221291 has 2 divisors, whose sum is σ = 21333221292. Its totient is φ = 21333221290.

The previous prime is 21333221263. The next prime is 21333221293. The reversal of 21333221291 is 19212233312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21333221291 - 2¹⁰ = 21333220267 is a prime.

Together with 21333221293, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21333221293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666610645 + 10666610646.

It is an arithmetic number, because the mean of its divisors is an integer number (10666610646).

Almost surely, 2^21333221291 is an apocalyptic number.

21333221291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21333221291 is an equidigital number, since it uses as much as digits as its factorization.

21333221291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 29.

The spelling of 21333221291 in words is "twenty-one billion, three hundred thirty-three million, two hundred twenty-one thousand, two hundred ninety-one".