811121 has 4 divisors (see below), whose sum is σ = 858852. Its totient is φ = 763392.

The previous prime is 811099. The next prime is 811123. The reversal of 811121 is 121118.

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 336400 + 474721 = 580^2 + 689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-811121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 811096 and 811105.

It is not an unprimeable number, because it can be changed into a prime (811123) 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, 23840 + ... + 23873.

It is an arithmetic number, because the mean of its divisors is an integer number (214713).

2⁸¹¹¹²¹ is an apocalyptic number.

It is an amenable number.

811121 is a deficient number, since it is larger than the sum of its proper divisors (47731).

811121 is a wasteful number, since it uses less digits than its factorization.

811121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47730.

The product of its digits is 16, while the sum is 14.

The square root of 811121 is about 900.6225624533. The cubic root of 811121 is about 93.2599579195.

Adding to 811121 its reverse (121118), we get a palindrome (932239).

The spelling of 811121 in words is "eight hundred eleven thousand, one hundred twenty-one".