11143991 has 4 divisors (see below), whose sum is σ = 11225472. Its totient is φ = 11062512.

The previous prime is 11143981. The next prime is 11143997. The reversal of 11143991 is 19934111.

11143991 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: 19934111 = 401 ⋅49711.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11143991 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 (11143997) 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, 40535 + ... + 40808.

It is an arithmetic number, because the mean of its divisors is an integer number (2806368).

Almost surely, 2^11143991 is an apocalyptic number.

11143991 is a deficient number, since it is larger than the sum of its proper divisors (81481).

11143991 is an equidigital number, since it uses as much as digits as its factorization.

11143991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81480.

The product of its digits is 972, while the sum is 29.

The square root of 11143991 is about 3338.2616733863. The cubic root of 11143991 is about 223.3642087459.

The spelling of 11143991 in words is "eleven million, one hundred forty-three thousand, nine hundred ninety-one".