840305 has 8 divisors (see below), whose sum is σ = 1052352. Its totient is φ = 642928.

The previous prime is 840299. The next prime is 840319. The reversal of 840305 is 503048.

840305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 840305 - 2⁴ = 840289 is a prime.

It is a super-2 number, since 2×840305² = 1412224986050, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840305.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3539 + ... + 3768.

It is an arithmetic number, because the mean of its divisors is an integer number (131544).

2⁸⁴⁰³⁰⁵ is an apocalyptic number.

It is an amenable number.

840305 is a deficient number, since it is larger than the sum of its proper divisors (212047).

840305 is a wasteful number, since it uses less digits than its factorization.

840305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7335.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 840305 is about 916.6815150313. The cubic root of 840305 is about 94.3652980392.

The spelling of 840305 in words is "eight hundred forty thousand, three hundred five".