21421122097 has 2 divisors, whose sum is σ = 21421122098. Its totient is φ = 21421122096.

The previous prime is 21421122089. The next prime is 21421122143. The reversal of 21421122097 is 79022112412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17016941601 + 4404180496 = 130449^2 + 66364^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421122097 - 2³ = 21421122089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21421122997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710561048 + 10710561049.

It is an arithmetic number, because the mean of its divisors is an integer number (10710561049).

Almost surely, 2^21421122097 is an apocalyptic number.

It is an amenable number.

21421122097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421122097 is an equidigital number, since it uses as much as digits as its factorization.

21421122097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The spelling of 21421122097 in words is "twenty-one billion, four hundred twenty-one million, one hundred twenty-two thousand, ninety-seven".