818381 has 4 divisors (see below), whose sum is σ = 820512. Its totient is φ = 816252.

The previous prime is 818371. The next prime is 818383. The reversal of 818381 is 183818.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 183818 = 2 ⋅91909.

It is a cyclic number.

It is not a de Polignac number, because 818381 - 2¹⁰ = 817357 is a prime.

It is a super-2 number, since 2×818381² = 1339494922322, which contains 22 as substring.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (818383) 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, 311 + ... + 1316.

It is an arithmetic number, because the mean of its divisors is an integer number (205128).

2⁸¹⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

818381 is a deficient number, since it is larger than the sum of its proper divisors (2131).

818381 is a wasteful number, since it uses less digits than its factorization.

818381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2130.

The product of its digits is 1536, while the sum is 29.

The square root of 818381 is about 904.6441289258. The cubic root of 818381 is about 93.5373753177.

The spelling of 818381 in words is "eight hundred eighteen thousand, three hundred eighty-one".