11165561 has 4 divisors (see below), whose sum is σ = 12180624. Its totient is φ = 10150500.

The previous prime is 11165543. The next prime is 11165591. The reversal of 11165561 is 16556111.

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 not a de Polignac number, because 11165561 - 2²² = 6971257 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 11165561.

It is not an unprimeable number, because it can be changed into a prime (11165591) 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, 507515 + ... + 507536.

It is an arithmetic number, because the mean of its divisors is an integer number (3045156).

Almost surely, 2^11165561 is an apocalyptic number.

11165561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11165561 is a deficient number, since it is larger than the sum of its proper divisors (1015063).

11165561 is a wasteful number, since it uses less digits than its factorization.

11165561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015062.

The product of its digits is 900, while the sum is 26.

The square root of 11165561 is about 3341.4908349418. The cubic root of 11165561 is about 223.5082283888.

The spelling of 11165561 in words is "eleven million, one hundred sixty-five thousand, five hundred sixty-one".