11809557 has 24 divisors (see below), whose sum is σ = 18467904. Its totient is φ = 7527168.

The previous prime is 11809547. The next prime is 11809561. The reversal of 11809557 is 75590811.

It is not a de Polignac number, because 11809557 - 2⁴ = 11809541 is a prime.

It is a super-4 number, since 4×11809557⁴ (a number of 29 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11809547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4533 + ... + 6645.

It is an arithmetic number, because the mean of its divisors is an integer number (769496).

Almost surely, 2^11809557 is an apocalyptic number.

It is an amenable number.

11809557 is a deficient number, since it is larger than the sum of its proper divisors (6658347).

11809557 is an equidigital number, since it uses as much as digits as its factorization.

11809557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2151 (or 2139 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 36.

The square root of 11809557 is about 3436.5036010457. The cubic root of 11809557 is about 227.7252577084.

The spelling of 11809557 in words is "eleven million, eight hundred nine thousand, five hundred fifty-seven".