21697710017 has 2 divisors, whose sum is σ = 21697710018. Its totient is φ = 21697710016.

The previous prime is 21697709983. The next prime is 21697710049. The reversal of 21697710017 is 71001779612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19288765456 + 2408944561 = 138884^2 + 49081^2 .

It is a cyclic number.

It is not a de Polignac number, because 21697710017 - 2⁶ = 21697709953 is a prime.

It is not a weakly prime, because it can be changed into another prime (21697710817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10848855008 + 10848855009.

It is an arithmetic number, because the mean of its divisors is an integer number (10848855009).

Almost surely, 2^21697710017 is an apocalyptic number.

It is an amenable number.

21697710017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21697710017 is an equidigital number, since it uses as much as digits as its factorization.

21697710017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37044, while the sum is 41.

The spelling of 21697710017 in words is "twenty-one billion, six hundred ninety-seven million, seven hundred ten thousand, seventeen".