818121 has 16 divisors (see below), whose sum is σ = 1187840. Its totient is φ = 498960.

The previous prime is 818113. The next prime is 818123. The reversal of 818121 is 121818.

It is not a de Polignac number, because 818121 - 2³ = 818113 is a prime.

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

It is the 905-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (818123) by changing a digit.

It is a nontrivial repunit in base 904.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1536 + ... + 1998.

It is an arithmetic number, because the mean of its divisors is an integer number (74240).

2⁸¹⁸¹²¹ is an apocalyptic number.

It is an amenable number.

818121 is a deficient number, since it is larger than the sum of its proper divisors (369719).

818121 is a wasteful number, since it uses less digits than its factorization.

818121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516.

The product of its digits is 128, while the sum is 21.

The square root of 818121 is about 904.5004145936. The cubic root of 818121 is about 93.5274686469.

Adding to 818121 its reverse (121818), we get a palindrome (939939).

It can be divided in two parts, 818 and 121, that added together give a palindrome (939).

The spelling of 818121 in words is "eight hundred eighteen thousand, one hundred twenty-one".