113781 has 16 divisors (see below), whose sum is σ = 169344. Its totient is φ = 67584.

The previous prime is 113779. The next prime is 113783. The reversal of 113781 is 187311.

It is an interprime number because it is at equal distance from previous prime (113779) and next prime (113783).

It is not a de Polignac number, because 113781 - 2¹ = 113779 is a prime.

It is a super-2 number, since 2×113781² = 25892231922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (113783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1125 + ... + 1221.

It is an arithmetic number, because the mean of its divisors is an integer number (10584).

2¹¹³⁷⁸¹ is an apocalyptic number.

It is an amenable number.

113781 is a deficient number, since it is larger than the sum of its proper divisors (55563).

113781 is a wasteful number, since it uses less digits than its factorization.

113781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140.

The product of its digits is 168, while the sum is 21.

The square root of 113781 is about 337.3143934077. The cubic root of 113781 is about 48.4570065727.

The spelling of 113781 in words is "one hundred thirteen thousand, seven hundred eighty-one".