857865008721 has 16 divisors (see below), whose sum is σ = 1307968632704. Its totient is φ = 489928915584.

The previous prime is 857865008719. The next prime is 857865008753. The reversal of 857865008721 is 127800568758.

It is not a de Polignac number, because 857865008721 - 2¹ = 857865008719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857865008701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11614846 + ... + 11688471.

It is an arithmetic number, because the mean of its divisors is an integer number (81748039544).

Almost surely, 2^857865008721 is an apocalyptic number.

It is an amenable number.

857865008721 is a deficient number, since it is larger than the sum of its proper divisors (450103623983).

857865008721 is a wasteful number, since it uses less digits than its factorization.

857865008721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23305080.

The product of its (nonzero) digits is 7526400, while the sum is 57.

The spelling of 857865008721 in words is "eight hundred fifty-seven billion, eight hundred sixty-five million, eight thousand, seven hundred twenty-one".