811143221 has 16 divisors (see below), whose sum is σ = 959067648. Its totient is φ = 671568000.

The previous prime is 811143191. The next prime is 811143259. The reversal of 811143221 is 122341118.

It is a cyclic number.

It is not a de Polignac number, because 811143221 - 2¹⁰ = 811142197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811145221) 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 15 ways as a sum of consecutive naturals, for example, 14996 + ... + 42978.

It is an arithmetic number, because the mean of its divisors is an integer number (59941728).

Almost surely, 2^811143221 is an apocalyptic number.

It is an amenable number.

811143221 is a deficient number, since it is larger than the sum of its proper divisors (147924427).

811143221 is a wasteful number, since it uses less digits than its factorization.

811143221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28132.

The product of its digits is 384, while the sum is 23.

The square root of 811143221 is about 28480.5762055475. The cubic root of 811143221 is about 932.6080954360.

Adding to 811143221 its reverse (122341118), we get a palindrome (933484339).

The spelling of 811143221 in words is "eight hundred eleven million, one hundred forty-three thousand, two hundred twenty-one".