33861 has 4 divisors (see below), whose sum is σ = 45152. Its totient is φ = 22572.

The previous prime is 33857. The next prime is 33863. The reversal of 33861 is 16833.

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.

It is not a de Polignac number, because 33861 - 2² = 33857 is a prime.

It is a super-2 number, since 2×33861² = 2293134642, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

33861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5641 + ... + 5646.

It is an arithmetic number, because the mean of its divisors is an integer number (11288).

2³³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

33861 is a deficient number, since it is larger than the sum of its proper divisors (11291).

33861 is a wasteful number, since it uses less digits than its factorization.

33861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11290.

The product of its digits is 432, while the sum is 21.

The square root of 33861 is about 184.0135864549. The cubic root of 33861 is about 32.3519100627.

The spelling of 33861 in words is "thirty-three thousand, eight hundred sixty-one".