1188391 has 8 divisors (see below), whose sum is σ = 1259280. Its totient is φ = 1119552.

The previous prime is 1188389. The next prime is 1188409. The reversal of 1188391 is 1938811.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1188391 - 2¹ = 1188389 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a zygodrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1188361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 771 + ... + 1723.

It is an arithmetic number, because the mean of its divisors is an integer number (157410).

2^1188391 is an apocalyptic number.

1188391 is a deficient number, since it is larger than the sum of its proper divisors (70889).

1188391 is an equidigital number, since it uses as much as digits as its factorization.

1188391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025.

The product of its digits is 1728, while the sum is 31.

The square root of 1188391 is about 1090.1334780659. The cubic root of 1188391 is about 105.9220680294.

The spelling of 1188391 in words is "one million, one hundred eighty-eight thousand, three hundred ninety-one".