85217855 has 16 divisors (see below), whose sum is σ = 108708480. Its totient is φ = 63908352.

The previous prime is 85217851. The next prime is 85217879. The reversal of 85217855 is 55871258.

It is a cyclic number.

It is not a de Polignac number, because 85217855 - 2² = 85217851 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85217851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21002 + ... + 24728.

It is an arithmetic number, because the mean of its divisors is an integer number (6794280).

Almost surely, 2^85217855 is an apocalyptic number.

85217855 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

85217855 is a deficient number, since it is larger than the sum of its proper divisors (23490625).

85217855 is a wasteful number, since it uses less digits than its factorization.

85217855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018.

The product of its digits is 112000, while the sum is 41.

The square root of 85217855 is about 9231.3517428381. The cubic root of 85217855 is about 440.0582825688.

The spelling of 85217855 in words is "eighty-five million, two hundred seventeen thousand, eight hundred fifty-five".