840145 has 4 divisors (see below), whose sum is σ = 1008180. Its totient is φ = 672112.

The previous prime is 840139. The next prime is 840149. The reversal of 840145 is 541048.

840145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 331776 + 508369 = 576^2 + 713^2 .

It is a cyclic number.

It is not a de Polignac number, because 840145 - 2³ = 840137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840149) 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, 84010 + ... + 84019.

It is an arithmetic number, because the mean of its divisors is an integer number (252045).

2⁸⁴⁰¹⁴⁵ is an apocalyptic number.

It is an amenable number.

840145 is a deficient number, since it is larger than the sum of its proper divisors (168035).

840145 is a wasteful number, since it uses less digits than its factorization.

840145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168034.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 840145 is about 916.5942395630. The cubic root of 840145 is about 94.3593083863.

The spelling of 840145 in words is "eight hundred forty thousand, one hundred forty-five".