8457443921 has 2 divisors, whose sum is σ = 8457443922. Its totient is φ = 8457443920.

The previous prime is 8457443893. The next prime is 8457443933. The reversal of 8457443921 is 1293447548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6181104400 + 2276339521 = 78620^2 + 47711^2 .

It is a cyclic number.

It is not a de Polignac number, because 8457443921 - 2³⁰ = 7383702097 is a prime.

It is not a weakly prime, because it can be changed into another prime (8457443941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4228721960 + 4228721961.

It is an arithmetic number, because the mean of its divisors is an integer number (4228721961).

Almost surely, 2^8457443921 is an apocalyptic number.

It is an amenable number.

8457443921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8457443921 is an equidigital number, since it uses as much as digits as its factorization.

8457443921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 47.

The square root of 8457443921 is about 91964.3622334217. The cubic root of 8457443921 is about 2037.4159837689.

The spelling of 8457443921 in words is "eight billion, four hundred fifty-seven million, four hundred forty-three thousand, nine hundred twenty-one".