857864765 has 4 divisors (see below), whose sum is σ = 1029437724. Its totient is φ = 686291808.

The previous prime is 857864743. The next prime is 857864773. The reversal of 857864765 is 567468758.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 567468758 = 2 ⋅283734379.

It can be written as a sum of positive squares in 2 ways, for example, as 557951641 + 299913124 = 23621^2 + 17318^2 .

It is a cyclic number.

It is not a de Polignac number, because 857864765 - 2²⁴ = 841087549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 857864765.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85786472 + ... + 85786481.

It is an arithmetic number, because the mean of its divisors is an integer number (257359431).

Almost surely, 2^857864765 is an apocalyptic number.

It is an amenable number.

857864765 is a deficient number, since it is larger than the sum of its proper divisors (171572959).

857864765 is a wasteful number, since it uses less digits than its factorization.

857864765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171572958.

The product of its digits is 11289600, while the sum is 56.

The square root of 857864765 is about 29289.3285173969. The cubic root of 857864765 is about 950.1808575336.

The spelling of 857864765 in words is "eight hundred fifty-seven million, eight hundred sixty-four thousand, seven hundred sixty-five".