811688085 has 24 divisors (see below), whose sum is σ = 1515152184. Its totient is φ = 399600000.

The previous prime is 811688083. The next prime is 811688179. The reversal of 811688085 is 580886118.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 106626276 + 705061809 = 10326^2 + 26553^2 .

It is not a de Polignac number, because 811688085 - 2¹ = 811688083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 811688085.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811688083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 693166 + ... + 694335.

It is an arithmetic number, because the mean of its divisors is an integer number (63131341).

Almost surely, 2^811688085 is an apocalyptic number.

It is an amenable number.

811688085 is a deficient number, since it is larger than the sum of its proper divisors (703464099).

811688085 is a wasteful number, since it uses less digits than its factorization.

811688085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1387525 (or 1387522 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 45.

The square root of 811688085 is about 28490.1401365455. The cubic root of 811688085 is about 932.8168669694.

It can be divided in two parts, 81168 and 8085, that added together give a triangular number (89253 = T₄₂₂).

The spelling of 811688085 in words is "eight hundred eleven million, six hundred eighty-eight thousand, eighty-five".