21244209097 has 2 divisors, whose sum is σ = 21244209098. Its totient is φ = 21244209096.

The previous prime is 21244209089. The next prime is 21244209127. The reversal of 21244209097 is 79090244212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11143758096 + 10100451001 = 105564^2 + 100501^2 .

It is a cyclic number.

It is not a de Polignac number, because 21244209097 - 2³ = 21244209089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21244209047) 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, 10622104548 + 10622104549.

It is an arithmetic number, because the mean of its divisors is an integer number (10622104549).

Almost surely, 2^21244209097 is an apocalyptic number.

It is an amenable number.

21244209097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21244209097 is an equidigital number, since it uses as much as digits as its factorization.

21244209097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 21244209097 in words is "twenty-one billion, two hundred forty-four million, two hundred nine thousand, ninety-seven".