111155000561 has 4 divisors (see below), whose sum is σ = 121260000624. Its totient is φ = 101050000500.

The previous prime is 111155000527. The next prime is 111155000617. The reversal of 111155000561 is 165000551111.

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 a de Polignac number, because none of the positive numbers 2^k-111155000561 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 111155000561.

It is not an unprimeable number, because it can be changed into a prime (111155000261) 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, 5052500015 + ... + 5052500036.

It is an arithmetic number, because the mean of its divisors is an integer number (30315000156).

Almost surely, 2^111155000561 is an apocalyptic number.

111155000561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111155000561 is a deficient number, since it is larger than the sum of its proper divisors (10105000063).

111155000561 is a wasteful number, since it uses less digits than its factorization.

111155000561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10105000062.

The product of its (nonzero) digits is 750, while the sum is 26.

Adding to 111155000561 its reverse (165000551111), we get a palindrome (276155551672).

The spelling of 111155000561 in words is "one hundred eleven billion, one hundred fifty-five million, five hundred sixty-one", and thus it is an aban number.