840091 has 8 divisors (see below), whose sum is σ = 982784. Its totient is φ = 703080.

The previous prime is 840083. The next prime is 840109. The reversal of 840091 is 190048.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 840091 - 2³ = 840083 is a prime.

It is a Duffinian number.

840091 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (840061) 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 7 ways as a sum of consecutive naturals, for example, 1095 + ... + 1696.

It is an arithmetic number, because the mean of its divisors is an integer number (122848).

2⁸⁴⁰⁰⁹¹ is an apocalyptic number.

840091 is a deficient number, since it is larger than the sum of its proper divisors (142693).

840091 is a wasteful number, since it uses less digits than its factorization.

840091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2841.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 840091 is about 916.5647822167. The cubic root of 840091 is about 94.3572867067.

The spelling of 840091 in words is "eight hundred forty thousand, ninety-one".