111561811 has 8 divisors (see below), whose sum is σ = 115527600. Its totient is φ = 107604000.

The previous prime is 111561797. The next prime is 111561829. The reversal of 111561811 is 118165111.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111561811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111561841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48436 + ... + 50686.

It is an arithmetic number, because the mean of its divisors is an integer number (14440950).

Almost surely, 2^111561811 is an apocalyptic number.

111561811 is a deficient number, since it is larger than the sum of its proper divisors (3965789).

111561811 is a wasteful number, since it uses less digits than its factorization.

111561811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3989.

The product of its digits is 240, while the sum is 25.

The square root of 111561811 is about 10562.2824711328. The cubic root of 111561811 is about 481.3990015713.

It can be divided in two parts, 1115 and 61811, that added together give a palindrome (62926).

The spelling of 111561811 in words is "one hundred eleven million, five hundred sixty-one thousand, eight hundred eleven".