9909857 has 2 divisors, whose sum is σ = 9909858. Its totient is φ = 9909856.

The previous prime is 9909847. The next prime is 9909859. The reversal of 9909857 is 7589099.

9909857 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., 7974976 + 1934881 = 2824^2 + 1391^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9909857 is a prime.

Together with 9909859, 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 (9909859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954928 + 4954929.

It is an arithmetic number, because the mean of its divisors is an integer number (4954929).

Almost surely, 2^9909857 is an apocalyptic number.

It is an amenable number.

9909857 is a deficient number, since it is larger than the sum of its proper divisors (1).

9909857 is an equidigital number, since it uses as much as digits as its factorization.

9909857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204120, while the sum is 47.

The square root of 9909857 is about 3147.9925349340. The cubic root of 9909857 is about 214.7941566910.

Adding to 9909857 its sum of digits (47), we get a square (9909904 = 3148²).

The spelling of 9909857 in words is "nine million, nine hundred nine thousand, eight hundred fifty-seven".