840591 has 16 divisors (see below), whose sum is σ = 1259520. Its totient is φ = 554040.

The previous prime is 840589. The next prime is 840601. The reversal of 840591 is 195048.

It is not a de Polignac number, because 840591 - 2¹ = 840589 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4306 + ... + 4496.

It is an arithmetic number, because the mean of its divisors is an integer number (78720).

2⁸⁴⁰⁵⁹¹ is an apocalyptic number.

840591 is a deficient number, since it is larger than the sum of its proper divisors (418929).

840591 is a wasteful number, since it uses less digits than its factorization.

840591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 840591 is about 916.8374992331. The cubic root of 840591 is about 94.3760026500.

It can be divided in two parts, 840 and 591, that added together give a triangular number (1431 = T₅₃).

The spelling of 840591 in words is "eight hundred forty thousand, five hundred ninety-one".