8921216809 has 8 divisors (see below), whose sum is σ = 8981209800. Its totient is φ = 8861264256.

The previous prime is 8921216807. The next prime is 8921216831. The reversal of 8921216809 is 9086121298.

8921216809 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 3708810000 + 5212406809 = 60900^2 + 72197^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8921216809 - 2¹ = 8921216807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8921216807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 527517 + ... + 544165.

It is an arithmetic number, because the mean of its divisors is an integer number (1122651225).

Almost surely, 2^8921216809 is an apocalyptic number.

It is an amenable number.

8921216809 is a deficient number, since it is larger than the sum of its proper divisors (59992991).

8921216809 is a wasteful number, since it uses less digits than its factorization.

8921216809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20219.

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 8921216809 is about 94452.1932461073. The cubic root of 8921216809 is about 2073.9965581525.

The spelling of 8921216809 in words is "eight billion, nine hundred twenty-one million, two hundred sixteen thousand, eight hundred nine".