850855509685 has 4 divisors (see below), whose sum is σ = 1021026611628. Its totient is φ = 680684407744.

The previous prime is 850855509641. The next prime is 850855509701. The reversal of 850855509685 is 586905558058.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 517740689764 + 333114819921 = 719542^2 + 577161^2 .

It is a cyclic number.

It is not a de Polignac number, because 850855509685 - 2²¹ = 850853412533 is a prime.

It is a super-2 number, since 2×850855509685² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85085550964 + ... + 85085550973.

It is an arithmetic number, because the mean of its divisors is an integer number (255256652907).

Almost surely, 2^850855509685 is an apocalyptic number.

It is an amenable number.

850855509685 is a deficient number, since it is larger than the sum of its proper divisors (170171101943).

850855509685 is a wasteful number, since it uses less digits than its factorization.

850855509685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170171101942.

The product of its (nonzero) digits is 86400000, while the sum is 64.

The spelling of 850855509685 in words is "eight hundred fifty billion, eight hundred fifty-five million, five hundred nine thousand, six hundred eighty-five".