821818916 has 24 divisors (see below), whose sum is σ = 1449073080. Its totient is φ = 407808000.

The previous prime is 821818891. The next prime is 821818919. The reversal of 821818916 is 619818128.

It can be written as a sum of positive squares in 4 ways, for example, as 37258816 + 784560100 = 6104^2 + 28010^2 .

It is not an unprimeable number, because it can be changed into a prime (821818919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512516 + ... + 514116.

It is an arithmetic number, because the mean of its divisors is an integer number (60378045).

Almost surely, 2^821818916 is an apocalyptic number.

It is an amenable number.

821818916 is a deficient number, since it is larger than the sum of its proper divisors (627254164).

821818916 is a wasteful number, since it uses less digits than its factorization.

821818916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2495 (or 2493 counting only the distinct ones).

The product of its digits is 55296, while the sum is 44.

The square root of 821818916 is about 28667.3841848188. The cubic root of 821818916 is about 936.6817193130.

The spelling of 821818916 in words is "eight hundred twenty-one million, eight hundred eighteen thousand, nine hundred sixteen".