9641865209 has 2 divisors, whose sum is σ = 9641865210. Its totient is φ = 9641865208.

The previous prime is 9641865173. The next prime is 9641865217. The reversal of 9641865209 is 9025681469.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9422973184 + 218892025 = 97072^2 + 14795^2 .

It is a cyclic number.

It is not a de Polignac number, because 9641865209 - 2²⁸ = 9373429753 is a prime.

It is a super-2 number, since 2×9641865209² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9640865209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4820932604 + 4820932605.

It is an arithmetic number, because the mean of its divisors is an integer number (4820932605).

Almost surely, 2^9641865209 is an apocalyptic number.

It is an amenable number.

9641865209 is a deficient number, since it is larger than the sum of its proper divisors (1).

9641865209 is an equidigital number, since it uses as much as digits as its factorization.

9641865209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 50.

The square root of 9641865209 is about 98192.9997963195. Note that the first 3 decimals coincide. The cubic root of 9641865209 is about 2128.4021320172.

The spelling of 9641865209 in words is "nine billion, six hundred forty-one million, eight hundred sixty-five thousand, two hundred nine".