21323221291 has 2 divisors, whose sum is σ = 21323221292. Its totient is φ = 21323221290.

The previous prime is 21323221289. The next prime is 21323221301. The reversal of 21323221291 is 19212232312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21323221291 - 2¹ = 21323221289 is a prime.

Together with 21323221289, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21323221201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661610645 + 10661610646.

It is an arithmetic number, because the mean of its divisors is an integer number (10661610646).

Almost surely, 2^21323221291 is an apocalyptic number.

21323221291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323221291 is an equidigital number, since it uses as much as digits as its factorization.

21323221291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 28.

The spelling of 21323221291 in words is "twenty-one billion, three hundred twenty-three million, two hundred twenty-one thousand, two hundred ninety-one".