85861 has 4 divisors (see below), whose sum is σ = 90400. Its totient is φ = 81324.

The previous prime is 85853. The next prime is 85889. The reversal of 85861 is 16858.

85861 = 58² + 59² + ... + 76².

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16858 = 2 ⋅8429.

It is a cyclic number.

It is not a de Polignac number, because 85861 - 2³ = 85853 is a prime.

It is a super-2 number, since 2×85861² = 14744222642, which contains 22 as substring.

It is a Duffinian number.

85861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2241 + ... + 2278.

It is an arithmetic number, because the mean of its divisors is an integer number (22600).

2⁸⁵⁸⁶¹ is an apocalyptic number.

It is an amenable number.

85861 is a deficient number, since it is larger than the sum of its proper divisors (4539).

85861 is a wasteful number, since it uses less digits than its factorization.

85861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4538.

The product of its digits is 1920, while the sum is 28.

The square root of 85861 is about 293.0204771002. The cubic root of 85861 is about 44.1162559213.

It can be divided in two parts, 858 and 61, that added together give a palindrome (919).

The spelling of 85861 in words is "eighty-five thousand, eight hundred sixty-one".