816443121 has 32 divisors (see below), whose sum is σ = 1244113920. Its totient is φ = 472405824.

The previous prime is 816443081. The next prime is 816443123. The reversal of 816443121 is 121344618.

It is not a de Polignac number, because 816443121 - 2⁹ = 816442609 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (816443123) 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 31 ways as a sum of consecutive naturals, for example, 45210 + ... + 60636.

It is an arithmetic number, because the mean of its divisors is an integer number (38878560).

Almost surely, 2^816443121 is an apocalyptic number.

It is an amenable number.

816443121 is a deficient number, since it is larger than the sum of its proper divisors (427670799).

816443121 is a wasteful number, since it uses less digits than its factorization.

816443121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15525.

The product of its digits is 4608, while the sum is 30.

The square root of 816443121 is about 28573.4688303678. The cubic root of 816443121 is about 934.6348659586.

Adding to 816443121 its reverse (121344618), we get a palindrome (937787739).

The spelling of 816443121 in words is "eight hundred sixteen million, four hundred forty-three thousand, one hundred twenty-one".