111731661 has 6 divisors (see below), whose sum is σ = 161390190. Its totient is φ = 74487768.

The previous prime is 111731651. The next prime is 111731671. The reversal of 111731661 is 166137111.

It is an interprime number because it is at equal distance from previous prime (111731651) and next prime (111731671).

It can be written as a sum of positive squares in only one way, i.e., 82246761 + 29484900 = 9069^2 + 5430^2 .

It is not a de Polignac number, because 111731661 - 2⁵ = 111731629 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111731651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6207306 + ... + 6207323.

It is an arithmetic number, because the mean of its divisors is an integer number (26898365).

Almost surely, 2^111731661 is an apocalyptic number.

It is an amenable number.

111731661 is a deficient number, since it is larger than the sum of its proper divisors (49658529).

111731661 is a wasteful number, since it uses less digits than its factorization.

111731661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12414635 (or 12414632 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 111731661 is about 10570.3198154077. The cubic root of 111731661 is about 481.6431835765.

Adding to 111731661 its reverse (166137111), we get a palindrome (277868772).

The spelling of 111731661 in words is "one hundred eleven million, seven hundred thirty-one thousand, six hundred sixty-one".