1155561 has 24 divisors (see below), whose sum is σ = 1792224. Its totient is φ = 656640.

The previous prime is 1155529. The next prime is 1155569. The reversal of 1155561 is 1655511.

It is not a de Polignac number, because 1155561 - 2⁵ = 1155529 is a prime.

It is a Curzon number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (1155569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11865 + ... + 11961.

It is an arithmetic number, because the mean of its divisors is an integer number (74676).

2^1155561 is an apocalyptic number.

1155561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1155561 is a deficient number, since it is larger than the sum of its proper divisors (636663).

1155561 is a wasteful number, since it uses less digits than its factorization.

1155561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 130 counting only the distinct ones).

The product of its digits is 750, while the sum is 24.

The square root of 1155561 is about 1074.9702321460. The cubic root of 1155561 is about 104.9375592474.

The spelling of 1155561 in words is "one million, one hundred fifty-five thousand, five hundred sixty-one".