111715561 has 4 divisors (see below), whose sum is σ = 111863124. Its totient is φ = 111568000.

The previous prime is 111715547. The next prime is 111715567. The reversal of 111715561 is 165517111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165517111 = 353 ⋅468887.

It can be written as a sum of positive squares in 2 ways, for example, as 44475561 + 67240000 = 6669^2 + 8200^2 .

It is a cyclic number.

It is not a de Polignac number, because 111715561 - 2⁷ = 111715433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111715567) 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 3 ways as a sum of consecutive naturals, for example, 72640 + ... + 74161.

It is an arithmetic number, because the mean of its divisors is an integer number (27965781).

Almost surely, 2^111715561 is an apocalyptic number.

It is an amenable number.

111715561 is a deficient number, since it is larger than the sum of its proper divisors (147563).

111715561 is an equidigital number, since it uses as much as digits as its factorization.

111715561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147562.

The product of its digits is 1050, while the sum is 28.

The square root of 111715561 is about 10569.5582216098. The cubic root of 111715561 is about 481.6200483026.

The spelling of 111715561 in words is "one hundred eleven million, seven hundred fifteen thousand, five hundred sixty-one".