11278991 has 4 divisors (see below), whose sum is σ = 11285712. Its totient is φ = 11272272.

The previous prime is 11278979. The next prime is 11279003. The reversal of 11278991 is 19987211.

11278991 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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19987211 = 263 ⋅75997.

It is an interprime number because it is at equal distance from previous prime (11278979) and next prime (11279003).

It is a cyclic number.

It is not a de Polignac number, because 11278991 - 2²² = 7084687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11278921) 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, 1526 + ... + 4988.

It is an arithmetic number, because the mean of its divisors is an integer number (2821428).

Almost surely, 2^11278991 is an apocalyptic number.

11278991 is a deficient number, since it is larger than the sum of its proper divisors (6721).

11278991 is an equidigital number, since it uses as much as digits as its factorization.

11278991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6720.

The product of its digits is 9072, while the sum is 38.

The square root of 11278991 is about 3358.4209087010. The cubic root of 11278991 is about 224.2625469039.

The spelling of 11278991 in words is "eleven million, two hundred seventy-eight thousand, nine hundred ninety-one".