18197171669 has 2 divisors, whose sum is σ = 18197171670. Its totient is φ = 18197171668.

The previous prime is 18197171653. The next prime is 18197171747. The reversal of 18197171669 is 96617179181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11548726225 + 6648445444 = 107465^2 + 81538^2 .

It is a cyclic number.

It is not a de Polignac number, because 18197171669 - 2⁴ = 18197171653 is a prime.

It is a super-2 number, since 2×18197171669² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18197171639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9098585834 + 9098585835.

It is an arithmetic number, because the mean of its divisors is an integer number (9098585835).

Almost surely, 2^18197171669 is an apocalyptic number.

It is an amenable number.

18197171669 is a deficient number, since it is larger than the sum of its proper divisors (1).

18197171669 is an equidigital number, since it uses as much as digits as its factorization.

18197171669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 56.

The spelling of 18197171669 in words is "eighteen billion, one hundred ninety-seven million, one hundred seventy-one thousand, six hundred sixty-nine".