85599991 has 2 divisors, whose sum is σ = 85599992. Its totient is φ = 85599990.

The previous prime is 85599979. The next prime is 85600027. The reversal of 85599991 is 19999558.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85599991 - 2¹¹ = 85597943 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85599911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42799995 + 42799996.

It is an arithmetic number, because the mean of its divisors is an integer number (42799996).

Almost surely, 2^85599991 is an apocalyptic number.

85599991 is a deficient number, since it is larger than the sum of its proper divisors (1).

85599991 is an equidigital number, since it uses as much as digits as its factorization.

85599991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1312200, while the sum is 55.

The square root of 85599991 is about 9252.0263185964. The cubic root of 85599991 is about 440.7150751987.

The spelling of 85599991 in words is "eighty-five million, five hundred ninety-nine thousand, nine hundred ninety-one".