811821416 has 24 divisors (see below), whose sum is σ = 1770682770. Its totient is φ = 347923296.

The previous prime is 811821391. The next prime is 811821431. The reversal of 811821416 is 614128118.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 718776100 + 93045316 = 26810^2 + 9646^2 .

It is a super-2 number, since 2×811821416² = 1318108022952490112, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1035095 + ... + 1035878.

Almost surely, 2^811821416 is an apocalyptic number.

It is an amenable number.

811821416 is an abundant number, since it is smaller than the sum of its proper divisors (958861354).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811821416 is a wasteful number, since it uses less digits than its factorization.

811821416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2070993 (or 2070982 counting only the distinct ones).

The product of its digits is 3072, while the sum is 32.

The square root of 811821416 is about 28492.4799903413. The cubic root of 811821416 is about 932.8679401993.

The spelling of 811821416 in words is "eight hundred eleven million, eight hundred twenty-one thousand, four hundred sixteen".