811798221 has 8 divisors (see below), whose sum is σ = 1165659040. Its totient is φ = 499568112.

The previous prime is 811798217. The next prime is 811798231. The reversal of 811798221 is 122897118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 811798221 - 2² = 811798217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 20815339 = 811798221 / (8 + 1 + 1 + 7 + 9 + 8 + 2 + 2 + 1).

It is a self number, because there is not a number n which added to its sum of digits gives 811798221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811798231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10407631 + ... + 10407708.

It is an arithmetic number, because the mean of its divisors is an integer number (145707380).

Almost surely, 2^811798221 is an apocalyptic number.

It is an amenable number.

811798221 is a deficient number, since it is larger than the sum of its proper divisors (353860819).

811798221 is a wasteful number, since it uses less digits than its factorization.

811798221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20815355.

The product of its digits is 16128, while the sum is 39.

The square root of 811798221 is about 28492.0729502084. The cubic root of 811798221 is about 932.8590556188.

The spelling of 811798221 in words is "eight hundred eleven million, seven hundred ninety-eight thousand, two hundred twenty-one".