840493 has 4 divisors (see below), whose sum is σ = 843228. Its totient is φ = 837760.

The previous prime is 840491. The next prime is 840523. The reversal of 840493 is 394048.

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

It can be written as a sum of positive squares in 2 ways, for example, as 104329 + 736164 = 323^2 + 858^2 .

It is a cyclic number.

It is not a de Polignac number, because 840493 - 2¹ = 840491 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 (840491) 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, 838 + ... + 1543.

It is an arithmetic number, because the mean of its divisors is an integer number (210807).

2⁸⁴⁰⁴⁹³ is an apocalyptic number.

It is an amenable number.

840493 is a deficient number, since it is larger than the sum of its proper divisors (2735).

840493 is a wasteful number, since it uses less digits than its factorization.

840493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2734.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 840493 is about 916.7840530899. The cubic root of 840493 is about 94.3723349100.

The spelling of 840493 in words is "eight hundred forty thousand, four hundred ninety-three".