111781889 has 4 divisors (see below), whose sum is σ = 112113924. Its totient is φ = 111449856.

The previous prime is 111781861. The next prime is 111781991. The reversal of 111781889 is 988187111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988187111 = 23 ⋅42964657.

It can be written as a sum of positive squares in 2 ways, for example, as 38850289 + 72931600 = 6233^2 + 8540^2 .

It is a cyclic number.

It is not a de Polignac number, because 111781889 - 2¹² = 111777793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111781819) 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, 165512 + ... + 166185.

It is an arithmetic number, because the mean of its divisors is an integer number (28028481).

Almost surely, 2^111781889 is an apocalyptic number.

It is an amenable number.

111781889 is a deficient number, since it is larger than the sum of its proper divisors (332035).

111781889 is an equidigital number, since it uses as much as digits as its factorization.

111781889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332034.

The product of its digits is 32256, while the sum is 44.

The square root of 111781889 is about 10572.6954462899. The cubic root of 111781889 is about 481.7153456041.

The spelling of 111781889 in words is "one hundred eleven million, seven hundred eighty-one thousand, eight hundred eighty-nine".