11157809 has 4 divisors (see below), whose sum is σ = 12016116. Its totient is φ = 10299504.

The previous prime is 11157803. The next prime is 11157823. The reversal of 11157809 is 90875111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90875111 = 47 ⋅1933513.

It can be written as a sum of positive squares in 2 ways, for example, as 1763584 + 9394225 = 1328^2 + 3065^2 .

It is a cyclic number.

It is not a de Polignac number, because 11157809 - 2⁴ = 11157793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11157803) 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, 429134 + ... + 429159.

It is an arithmetic number, because the mean of its divisors is an integer number (3004029).

Almost surely, 2^11157809 is an apocalyptic number.

It is an amenable number.

11157809 is a deficient number, since it is larger than the sum of its proper divisors (858307).

11157809 is an equidigital number, since it uses as much as digits as its factorization.

11157809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 858306.

The product of its (nonzero) digits is 2520, while the sum is 32.

The square root of 11157809 is about 3340.3306722539. The cubic root of 11157809 is about 223.4564908207.

The spelling of 11157809 in words is "eleven million, one hundred fifty-seven thousand, eight hundred nine".