8813921 has 2 divisors, whose sum is σ = 8813922. Its totient is φ = 8813920.

The previous prime is 8813897. The next prime is 8813923. The reversal of 8813921 is 1293188.

8813921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6964321 + 1849600 = 2639^2 + 1360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8813921 is a prime.

Together with 8813923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8813923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4406960 + 4406961.

It is an arithmetic number, because the mean of its divisors is an integer number (4406961).

Almost surely, 2^8813921 is an apocalyptic number.

It is an amenable number.

8813921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8813921 is an equidigital number, since it uses as much as digits as its factorization.

8813921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 32.

The square root of 8813921 is about 2968.8248516880. The cubic root of 8813921 is about 206.5648321859.

The spelling of 8813921 in words is "eight million, eight hundred thirteen thousand, nine hundred twenty-one".