85122991 has 2 divisors, whose sum is σ = 85122992. Its totient is φ = 85122990.

The previous prime is 85122971. The next prime is 85123007. The reversal of 85122991 is 19922158.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 85122991 - 2¹¹ = 85120943 is a prime.

It is equal to p_4950397 and since 85122991 and 4950397 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 85122991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85122911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42561495 + 42561496.

It is an arithmetic number, because the mean of its divisors is an integer number (42561496).

Almost surely, 2^85122991 is an apocalyptic number.

85122991 is a deficient number, since it is larger than the sum of its proper divisors (1).

85122991 is an equidigital number, since it uses as much as digits as its factorization.

85122991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 37.

The square root of 85122991 is about 9226.2121696826. The cubic root of 85122991 is about 439.8949318686.

The spelling of 85122991 in words is "eighty-five million, one hundred twenty-two thousand, nine hundred ninety-one".