111206111561 has 4 divisors (see below), whose sum is σ = 111428970000. Its totient is φ = 110983253124.

The previous prime is 111206111437. The next prime is 111206111593. The reversal of 111206111561 is 165111602111.

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, and also an emirpimes, since its reverse is a distinct semiprime: 165111602111 = 17 ⋅9712447183.

It is a cyclic number.

It is not a de Polignac number, because 111206111561 - 2¹⁴ = 111206095177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 111206111561.

It is not an unprimeable number, because it can be changed into a prime (111206113561) 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, 111428471 + ... + 111429468.

It is an arithmetic number, because the mean of its divisors is an integer number (27857242500).

Almost surely, 2^111206111561 is an apocalyptic number.

It is an amenable number.

111206111561 is a deficient number, since it is larger than the sum of its proper divisors (222858439).

111206111561 is an equidigital number, since it uses as much as digits as its factorization.

111206111561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222858438.

The product of its (nonzero) digits is 360, while the sum is 26.

Adding to 111206111561 its reverse (165111602111), we get a palindrome (276317713672).

The spelling of 111206111561 in words is "one hundred eleven billion, two hundred six million, one hundred eleven thousand, five hundred sixty-one".