21122010491 has 2 divisors, whose sum is σ = 21122010492. Its totient is φ = 21122010490.

The previous prime is 21122010401. The next prime is 21122010577. The reversal of 21122010491 is 19401022112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21122010491 - 2¹⁴ = 21121994107 is a prime.

It is a super-2 number, since 2×21122010491² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21122010401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561005245 + 10561005246.

It is an arithmetic number, because the mean of its divisors is an integer number (10561005246).

Almost surely, 2^21122010491 is an apocalyptic number.

21122010491 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122010491 is an equidigital number, since it uses as much as digits as its factorization.

21122010491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 21122010491 in words is "twenty-one billion, one hundred twenty-two million, ten thousand, four hundred ninety-one".