1105505561 has 4 divisors (see below), whose sum is σ = 1122005712. Its totient is φ = 1089005412.

The previous prime is 1105505543. The next prime is 1105505567. The reversal of 1105505561 is 1655055011.

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 an emirpimes, since its reverse is a distinct semiprime: 1655055011 = 2011 ⋅823001.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1105505561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1105505567) 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, 8249975 + ... + 8250108.

It is an arithmetic number, because the mean of its divisors is an integer number (280501428).

Almost surely, 2^1105505561 is an apocalyptic number.

It is an amenable number.

1105505561 is a deficient number, since it is larger than the sum of its proper divisors (16500151).

1105505561 is an equidigital number, since it uses as much as digits as its factorization.

1105505561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16500150.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 1105505561 is about 33249.1437634114. The cubic root of 1105505561 is about 1033.9994565804. Note that the first 3 decimals are identical.

The spelling of 1105505561 in words is "one billion, one hundred five million, five hundred five thousand, five hundred sixty-one".