21063909697 has 2 divisors, whose sum is σ = 21063909698. Its totient is φ = 21063909696.

The previous prime is 21063909673. The next prime is 21063909719. The reversal of 21063909697 is 79690936012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10774647601 + 10289262096 = 103801^2 + 101436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21063909697 - 2²³ = 21055521089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21063909617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10531954848 + 10531954849.

It is an arithmetic number, because the mean of its divisors is an integer number (10531954849).

Almost surely, 2^21063909697 is an apocalyptic number.

It is an amenable number.

21063909697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21063909697 is an equidigital number, since it uses as much as digits as its factorization.

21063909697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1102248, while the sum is 52.

The spelling of 21063909697 in words is "twenty-one billion, sixty-three million, nine hundred nine thousand, six hundred ninety-seven".