857250009 has 24 divisors (see below), whose sum is σ = 1543793472. Its totient is φ = 445324320.

The previous prime is 857250001. The next prime is 857250049. The reversal of 857250009 is 900052758.

857250009 is a `hidden beast` number, since 85 + 72 + 500 + 0 + 9 = 666.

It is not a de Polignac number, because 857250009 - 2³ = 857250001 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (857250001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 617814 + ... + 619199.

It is an arithmetic number, because the mean of its divisors is an integer number (64324728).

Almost surely, 2^857250009 is an apocalyptic number.

It is an amenable number.

857250009 is a deficient number, since it is larger than the sum of its proper divisors (686543463).

857250009 is a wasteful number, since it uses less digits than its factorization.

857250009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237037 (or 1237034 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The square root of 857250009 is about 29278.8320976094. The cubic root of 857250009 is about 949.9538330289.

The spelling of 857250009 in words is "eight hundred fifty-seven million, two hundred fifty thousand, nine".