85644311209 has 2 divisors, whose sum is σ = 85644311210. Its totient is φ = 85644311208.

The previous prime is 85644311149. The next prime is 85644311231. The reversal of 85644311209 is 90211344658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76084947225 + 9559363984 = 275835^2 + 97772^2 .

It is a cyclic number.

It is not a de Polignac number, because 85644311209 - 2³⁵ = 51284572841 is a prime.

It is not a weakly prime, because it can be changed into another prime (85644311279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42822155604 + 42822155605.

It is an arithmetic number, because the mean of its divisors is an integer number (42822155605).

Almost surely, 2^85644311209 is an apocalyptic number.

It is an amenable number.

85644311209 is a deficient number, since it is larger than the sum of its proper divisors (1).

85644311209 is an equidigital number, since it uses as much as digits as its factorization.

85644311209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 85644311209 in words is "eighty-five billion, six hundred forty-four million, three hundred eleven thousand, two hundred nine".