85781181 has 24 divisors (see below), whose sum is σ = 122041920. Its totient is φ = 53581824.

The previous prime is 85781177. The next prime is 85781183. The reversal of 85781181 is 18118758.

It is not a de Polignac number, because 85781181 - 2² = 85781177 is a prime.

It is a super-2 number, since 2×85781181² = 14716822027509522, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85781183) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 111165 + ... + 111933.

It is an arithmetic number, because the mean of its divisors is an integer number (5085080).

Almost surely, 2^85781181 is an apocalyptic number.

It is an amenable number.

85781181 is a deficient number, since it is larger than the sum of its proper divisors (36260739).

85781181 is a wasteful number, since it uses less digits than its factorization.

85781181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913 (or 894 counting only the distinct ones).

The product of its digits is 17920, while the sum is 39.

The square root of 85781181 is about 9261.8130514495. The cubic root of 85781181 is about 441.0258107795.

The spelling of 85781181 in words is "eighty-five million, seven hundred eighty-one thousand, one hundred eighty-one".