816812219 has 4 divisors (see below), whose sum is σ = 835807896. Its totient is φ = 797816544.

The previous prime is 816812177. The next prime is 816812279. The reversal of 816812219 is 912218618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 912218618 = 2 ⋅456109309.

It is a cyclic number.

It is not a de Polignac number, because 816812219 - 2¹² = 816808123 is a prime.

It is a super-2 number, since 2×816812219² = 1334364402215407922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816812279) 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, 9497774 + ... + 9497859.

It is an arithmetic number, because the mean of its divisors is an integer number (208951974).

Almost surely, 2^816812219 is an apocalyptic number.

816812219 is a deficient number, since it is larger than the sum of its proper divisors (18995677).

816812219 is a wasteful number, since it uses less digits than its factorization.

816812219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18995676.

The product of its digits is 13824, while the sum is 38.

The square root of 816812219 is about 28579.9268543501. The cubic root of 816812219 is about 934.7756881335.

The spelling of 816812219 in words is "eight hundred sixteen million, eight hundred twelve thousand, two hundred nineteen".