11871391 has 4 divisors (see below), whose sum is σ = 13567312. Its totient is φ = 10175472.

The previous prime is 11871373. The next prime is 11871403. The reversal of 11871391 is 19317811.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11871391 - 2¹⁹ = 11347103 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 (11871361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 847950 + ... + 847963.

It is an arithmetic number, because the mean of its divisors is an integer number (3391828).

Almost surely, 2^11871391 is an apocalyptic number.

11871391 is a deficient number, since it is larger than the sum of its proper divisors (1695921).

11871391 is an equidigital number, since it uses as much as digits as its factorization.

11871391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1695920.

The product of its digits is 1512, while the sum is 31.

The square root of 11871391 is about 3445.4884994729. The cubic root of 11871391 is about 228.1220171249.

The spelling of 11871391 in words is "eleven million, eight hundred seventy-one thousand, three hundred ninety-one".