1131605 has 8 divisors (see below), whose sum is σ = 1437912. Its totient is φ = 851968.

The previous prime is 1131569. The next prime is 1131617. The reversal of 1131605 is 5061311.

It can be written as a sum of positive squares in 4 ways, for example, as 167281 + 964324 = 409^2 + 982^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1131605 - 2¹⁰ = 1130581 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a plaindrome in base 16.

It is a zygodrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6572 + ... + 6741.

It is an arithmetic number, because the mean of its divisors is an integer number (179739).

2^1131605 is an apocalyptic number.

It is an amenable number.

1131605 is a deficient number, since it is larger than the sum of its proper divisors (306307).

1131605 is a wasteful number, since it uses less digits than its factorization.

1131605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13335.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 1131605 is about 1063.7692418941. The cubic root of 1131605 is about 104.2073341655.

Adding to 1131605 its reverse (5061311), we get a palindrome (6192916).

The spelling of 1131605 in words is "one million, one hundred thirty-one thousand, six hundred five".