840065 has 4 divisors (see below), whose sum is σ = 1008084. Its totient is φ = 672048.

The previous prime is 840061. The next prime is 840067. The reversal of 840065 is 560048.

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 478864 + 361201 = 692^2 + 601^2 .

It is a cyclic number.

It is not a de Polignac number, because 840065 - 2² = 840061 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 840065.

It is not an unprimeable number, because it can be changed into a prime (840061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84002 + ... + 84011.

It is an arithmetic number, because the mean of its divisors is an integer number (252021).

2⁸⁴⁰⁰⁶⁵ is an apocalyptic number.

It is an amenable number.

840065 is a deficient number, since it is larger than the sum of its proper divisors (168019).

840065 is a wasteful number, since it uses less digits than its factorization.

840065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168018.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 840065 is about 916.5505987124. The cubic root of 840065 is about 94.3563132746.

The spelling of 840065 in words is "eight hundred forty thousand, sixty-five".