391493 has 4 divisors (see below), whose sum is σ = 414540. Its totient is φ = 368448.

The previous prime is 391487. The next prime is 391519. The reversal of 391493 is 394193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 394193 = 19 ⋅20747.

It can be written as a sum of positive squares in 2 ways, for example, as 332929 + 58564 = 577^2 + 242^2 .

It is a cyclic number.

It is not a de Polignac number, because 391493 - 2¹² = 387397 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 (391403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11498 + ... + 11531.

It is an arithmetic number, because the mean of its divisors is an integer number (103635).

2³⁹¹⁴⁹³ is an apocalyptic number.

It is an amenable number.

391493 is a deficient number, since it is larger than the sum of its proper divisors (23047).

391493 is a wasteful number, since it uses less digits than its factorization.

391493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23046.

The product of its digits is 2916, while the sum is 29.

The square root of 391493 is about 625.6940146749. The cubic root of 391493 is about 73.1545484110.

The spelling of 391493 in words is "three hundred ninety-one thousand, four hundred ninety-three".