111681491 has 4 divisors (see below), whose sum is σ = 116537232. Its totient is φ = 106825752.

The previous prime is 111681481. The next prime is 111681497. The reversal of 111681491 is 194186111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194186111 = 7 ⋅27740873.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111681491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111681497) 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, 2427836 + ... + 2427881.

It is an arithmetic number, because the mean of its divisors is an integer number (29134308).

Almost surely, 2^111681491 is an apocalyptic number.

111681491 is a deficient number, since it is larger than the sum of its proper divisors (4855741).

111681491 is an equidigital number, since it uses as much as digits as its factorization.

111681491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4855740.

The product of its digits is 1728, while the sum is 32.

The square root of 111681491 is about 10567.9463946407. The cubic root of 111681491 is about 481.5710832845.

The spelling of 111681491 in words is "one hundred eleven million, six hundred eighty-one thousand, four hundred ninety-one".