999997857 has 6 divisors (see below), whose sum is σ = 1444441362. Its totient is φ = 666665232.

The previous prime is 999997811. The next prime is 999997871. The reversal of 999997857 is 758799999.

999997857 is digitally balanced in base 2, 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 only one way, i.e., 724471056 + 275526801 = 26916^2 + 16599^2 .

It is not a de Polignac number, because 999997857 - 2⁶ = 999997793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999997357) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55555428 + ... + 55555445.

It is an arithmetic number, because the mean of its divisors is an integer number (240740227).

Almost surely, 2^999997857 is an apocalyptic number.

It is an amenable number.

999997857 is a deficient number, since it is larger than the sum of its proper divisors (444443505).

999997857 is a wasteful number, since it uses less digits than its factorization.

999997857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111110879 (or 111110876 counting only the distinct ones).

The product of its digits is 115736040, while the sum is 72.

The square root of 999997857 is about 31622.7427178605. The cubic root of 999997857 is about 999.9992856662. Note that the first 3 decimals are identical.

The spelling of 999997857 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, eight hundred fifty-seven".