111617561 has 4 divisors (see below), whose sum is σ = 121764624. Its totient is φ = 101470500.

The previous prime is 111617543. The next prime is 111617573. The reversal of 111617561 is 165716111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 111617561 - 2¹⁸ = 111355417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111617501) 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, 5073515 + ... + 5073536.

It is an arithmetic number, because the mean of its divisors is an integer number (30441156).

Almost surely, 2^111617561 is an apocalyptic number.

111617561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111617561 is a deficient number, since it is larger than the sum of its proper divisors (10147063).

111617561 is a wasteful number, since it uses less digits than its factorization.

111617561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10147062.

The product of its digits is 1260, while the sum is 29.

The square root of 111617561 is about 10564.9212491149. The cubic root of 111617561 is about 481.4791769313.

The spelling of 111617561 in words is "one hundred eleven million, six hundred seventeen thousand, five hundred sixty-one".