818401 has 4 divisors (see below), whose sum is σ = 838404. Its totient is φ = 798400.

The previous prime is 818399. The next prime is 818413. The reversal of 818401 is 104818.

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 389376 + 429025 = 624^2 + 655^2 .

It is a cyclic number.

It is not a de Polignac number, because 818401 - 2¹ = 818399 is a prime.

It is an Ulam number.

It is a Duffinian number.

818401 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (818101) 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 3 ways as a sum of consecutive naturals, for example, 9940 + ... + 10021.

It is an arithmetic number, because the mean of its divisors is an integer number (209601).

2⁸¹⁸⁴⁰¹ is an apocalyptic number.

It is an amenable number.

818401 is a deficient number, since it is larger than the sum of its proper divisors (20003).

818401 is a wasteful number, since it uses less digits than its factorization.

818401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20002.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 818401 is about 904.6551829288. The cubic root of 818401 is about 93.5381372824.

The spelling of 818401 in words is "eight hundred eighteen thousand, four hundred one".