11156809 has 4 divisors (see below), whose sum is σ = 11309716. Its totient is φ = 11003904.

The previous prime is 11156801. The next prime is 11156833. The reversal of 11156809 is 90865111.

11156809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90865111 = 23 ⋅3950657.

It can be written as a sum of positive squares in 2 ways, for example, as 5382400 + 5774409 = 2320^2 + 2403^2 .

It is a cyclic number.

It is not a de Polignac number, because 11156809 - 2³ = 11156801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11156801) 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, 76344 + ... + 76489.

It is an arithmetic number, because the mean of its divisors is an integer number (2827429).

Almost surely, 2^11156809 is an apocalyptic number.

It is an amenable number.

11156809 is a deficient number, since it is larger than the sum of its proper divisors (152907).

11156809 is an equidigital number, since it uses as much as digits as its factorization.

11156809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152906.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 11156809 is about 3340.1809831205. The cubic root of 11156809 is about 223.4498149830.

The spelling of 11156809 in words is "eleven million, one hundred fifty-six thousand, eight hundred nine".