109861 has 4 divisors (see below), whose sum is σ = 111724. Its totient is φ = 108000.

The previous prime is 109859. The next prime is 109873. The reversal of 109861 is 168901.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8100 + 101761 = 90^2 + 319^2 .

It is a 3-Lehmer number, since φ(109861) divides (109861-1)³.

It is a cyclic number.

It is not a de Polignac number, because 109861 - 2¹ = 109859 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 (109831) 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, 840 + ... + 961.

It is an arithmetic number, because the mean of its divisors is an integer number (27931).

2¹⁰⁹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

109861 is a deficient number, since it is larger than the sum of its proper divisors (1863).

109861 is an equidigital number, since it uses as much as digits as its factorization.

109861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1862.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 109861 is about 331.4528624103. The cubic root of 109861 is about 47.8940080225.

The spelling of 109861 in words is "one hundred nine thousand, eight hundred sixty-one".