857943642865 has 8 divisors (see below), whose sum is σ = 1032292514088. Its totient is φ = 684514819200.

The previous prime is 857943642847. The next prime is 857943642869. The reversal of 857943642865 is 568246349758.

857943642865 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 4 ways, for example, as 306031346401 + 551912296464 = 553201^2 + 742908^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 857943642865 - 2⁵ = 857943642833 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 857943642865.

It is not an unprimeable number, because it can be changed into a prime (857943642869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230009836 + ... + 230013565.

It is an arithmetic number, because the mean of its divisors is an integer number (129036564261).

Almost surely, 2^857943642865 is an apocalyptic number.

It is an amenable number.

857943642865 is a deficient number, since it is larger than the sum of its proper divisors (174348871223).

857943642865 is a wasteful number, since it uses less digits than its factorization.

857943642865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460023779.

The product of its digits is 348364800, while the sum is 67.

The spelling of 857943642865 in words is "eight hundred fifty-seven billion, nine hundred forty-three million, six hundred forty-two thousand, eight hundred sixty-five".