1198391 has 4 divisors (see below), whose sum is σ = 1203312. Its totient is φ = 1193472.

The previous prime is 1198363. The next prime is 1198397. The reversal of 1198391 is 1938911.

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 1198391 - 2¹⁰ = 1197367 is a prime.

It is a super-2 number, since 2×1198391² = 2872281977762, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1198397) 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, 2075 + ... + 2588.

It is an arithmetic number, because the mean of its divisors is an integer number (300828).

2^1198391 is an apocalyptic number.

1198391 is a deficient number, since it is larger than the sum of its proper divisors (4921).

1198391 is an equidigital number, since it uses as much as digits as its factorization.

1198391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4920.

The product of its digits is 1944, while the sum is 32.

The square root of 1198391 is about 1094.7104640041. The cubic root of 1198391 is about 106.2183407405.

The spelling of 1198391 in words is "one million, one hundred ninety-eight thousand, three hundred ninety-one".