21522399491 has 2 divisors, whose sum is σ = 21522399492. Its totient is φ = 21522399490.

The previous prime is 21522399467. The next prime is 21522399499. The reversal of 21522399491 is 19499322512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21522399491 - 2²² = 21518205187 is a prime.

It is not a weakly prime, because it can be changed into another prime (21522399499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761199745 + 10761199746.

It is an arithmetic number, because the mean of its divisors is an integer number (10761199746).

Almost surely, 2^21522399491 is an apocalyptic number.

21522399491 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522399491 is an equidigital number, since it uses as much as digits as its factorization.

21522399491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 47.

The spelling of 21522399491 in words is "twenty-one billion, five hundred twenty-two million, three hundred ninety-nine thousand, four hundred ninety-one".