21943586897 has 2 divisors, whose sum is σ = 21943586898. Its totient is φ = 21943586896.

The previous prime is 21943586867. The next prime is 21943586911. The reversal of 21943586897 is 79868534912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20356440976 + 1587145921 = 142676^2 + 39839^2 .

It is a cyclic number.

It is not a de Polignac number, because 21943586897 - 2²² = 21939392593 is a prime.

It is not a weakly prime, because it can be changed into another prime (21943586867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10971793448 + 10971793449.

It is an arithmetic number, because the mean of its divisors is an integer number (10971793449).

Almost surely, 2^21943586897 is an apocalyptic number.

It is an amenable number.

21943586897 is a deficient number, since it is larger than the sum of its proper divisors (1).

21943586897 is an equidigital number, since it uses as much as digits as its factorization.

21943586897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26127360, while the sum is 62.

The spelling of 21943586897 in words is "twenty-one billion, nine hundred forty-three million, five hundred eighty-six thousand, eight hundred ninety-seven".