85561 has 8 divisors (see below), whose sum is σ = 103680. Its totient is φ = 68928.

The previous prime is 85549. The next prime is 85571. The reversal of 85561 is 16558.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 85561 - 2⁹ = 85049 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241 + ... + 478.

It is an arithmetic number, because the mean of its divisors is an integer number (12960).

2⁸⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

85561 is a deficient number, since it is larger than the sum of its proper divisors (18119).

85561 is a wasteful number, since it uses less digits than its factorization.

85561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743.

The product of its digits is 1200, while the sum is 25.

The square root of 85561 is about 292.5081195454. The cubic root of 85561 is about 44.0648149447.

It can be divided in two parts, 85 and 561, that added together give a palindrome (646).

The spelling of 85561 in words is "eighty-five thousand, five hundred sixty-one".