85165991693 has 2 divisors, whose sum is σ = 85165991694. Its totient is φ = 85165991692.

The previous prime is 85165991681. The next prime is 85165991707. The reversal of 85165991693 is 39619956158.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83730945769 + 1435045924 = 289363^2 + 37882^2 .

It is a cyclic number.

It is not a de Polignac number, because 85165991693 - 2²⁰ = 85164943117 is a prime.

It is a super-2 number, since 2×85165991693² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85165991653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42582995846 + 42582995847.

It is an arithmetic number, because the mean of its divisors is an integer number (42582995847).

Almost surely, 2^85165991693 is an apocalyptic number.

It is an amenable number.

85165991693 is a deficient number, since it is larger than the sum of its proper divisors (1).

85165991693 is an equidigital number, since it uses as much as digits as its factorization.

85165991693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15746400, while the sum is 62.

The spelling of 85165991693 in words is "eighty-five billion, one hundred sixty-five million, nine hundred ninety-one thousand, six hundred ninety-three".