118781 has 4 divisors (see below), whose sum is σ = 127932. Its totient is φ = 109632.

The previous prime is 118757. The next prime is 118787. The reversal of 118781 is 187811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187811 = 13 ⋅14447.

It can be written as a sum of positive squares in 2 ways, for example, as 7225 + 111556 = 85^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 118781 - 2⁶ = 118717 is a prime.

It is a super-2 number, since 2×118781² = 28217851922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 118781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (118787) 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, 4556 + ... + 4581.

It is an arithmetic number, because the mean of its divisors is an integer number (31983).

2¹¹⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

118781 is a deficient number, since it is larger than the sum of its proper divisors (9151).

118781 is an equidigital number, since it uses as much as digits as its factorization.

118781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150.

The product of its digits is 448, while the sum is 26.

The square root of 118781 is about 344.6461953946. The cubic root of 118781 is about 49.1566553717.

The spelling of 118781 in words is "one hundred eighteen thousand, seven hundred eighty-one".