391189 has 4 divisors (see below), whose sum is σ = 403840. Its totient is φ = 378540.

The previous prime is 391177. The next prime is 391199. The reversal of 391189 is 981193.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 981193 = 73 ⋅13441.

It is a cyclic number.

It is not a de Polignac number, because 391189 - 2¹¹ = 389141 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 12619 = 391189 / (3 + 9 + 1 + 1 + 8 + 9).

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 391189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391159) 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, 6279 + ... + 6340.

It is an arithmetic number, because the mean of its divisors is an integer number (100960).

2³⁹¹¹⁸⁹ is an apocalyptic number.

It is an amenable number.

391189 is a deficient number, since it is larger than the sum of its proper divisors (12651).

391189 is a wasteful number, since it uses less digits than its factorization.

391189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12650.

The product of its digits is 1944, while the sum is 31.

The square root of 391189 is about 625.4510372523. The cubic root of 391189 is about 73.1356083180.

The spelling of 391189 in words is "three hundred ninety-one thousand, one hundred eighty-nine".