840401 has 4 divisors (see below), whose sum is σ = 842352. Its totient is φ = 838452.

The previous prime is 840353. The next prime is 840439. The reversal of 840401 is 104048.

It is a happy number.

840401 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 840401 - 2¹⁴ = 824017 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 840401.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840401.

It is not an unprimeable number, because it can be changed into a prime (840451) 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, 11 + ... + 1296.

It is an arithmetic number, because the mean of its divisors is an integer number (210588).

2⁸⁴⁰⁴⁰¹ is an apocalyptic number.

It is an amenable number.

840401 is a deficient number, since it is larger than the sum of its proper divisors (1951).

840401 is a wasteful number, since it uses less digits than its factorization.

840401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1950.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 840401 is about 916.7338763240. The cubic root of 840401 is about 94.3688914661.

Adding to 840401 its reverse (104048), we get a palindrome (944449).

The spelling of 840401 in words is "eight hundred forty thousand, four hundred one".