1105111661 has 4 divisors (see below), whose sum is σ = 1105185312. Its totient is φ = 1105038012.

The previous prime is 1105111643. The next prime is 1105111669. The reversal of 1105111661 is 1661115011.

It is a happy number.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1661115011 = 181 ⋅9177431.

It is a cyclic number.

It is not a de Polignac number, because 1105111661 - 2²² = 1100917357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1105111669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5351 + ... + 47316.

It is an arithmetic number, because the mean of its divisors is an integer number (276296328).

Almost surely, 2^1105111661 is an apocalyptic number.

It is an amenable number.

1105111661 is a deficient number, since it is larger than the sum of its proper divisors (73651).

1105111661 is an equidigital number, since it uses as much as digits as its factorization.

1105111661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73650.

The product of its (nonzero) digits is 180, while the sum is 23.

The square root of 1105111661 is about 33243.2197748654. The cubic root of 1105111661 is about 1033.8766347139.

Adding to 1105111661 its reverse (1661115011), we get a palindrome (2766226672).

The spelling of 1105111661 in words is "one billion, one hundred five million, one hundred eleven thousand, six hundred sixty-one".