813220899 has 4 divisors (see below), whose sum is σ = 1084294536. Its totient is φ = 542147264.

The previous prime is 813220897. The next prime is 813220901. The reversal of 813220899 is 998022318.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (813220897) and next prime (813220901).

It is a cyclic number.

It is not a de Polignac number, because 813220899 - 2¹ = 813220897 is a prime.

It is a super-3 number, since 3×813220899³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 813220899.

It is not an unprimeable number, because it can be changed into a prime (813220897) 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, 135536814 + ... + 135536819.

It is an arithmetic number, because the mean of its divisors is an integer number (271073634).

Almost surely, 2^813220899 is an apocalyptic number.

813220899 is a deficient number, since it is larger than the sum of its proper divisors (271073637).

813220899 is a wasteful number, since it uses less digits than its factorization.

813220899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271073636.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 813220899 is about 28517.0282287618. The cubic root of 813220899 is about 933.4036833735.

The spelling of 813220899 in words is "eight hundred thirteen million, two hundred twenty thousand, eight hundred ninety-nine".