85511729 has 4 divisors (see below), whose sum is σ = 85545060. Its totient is φ = 85478400.

The previous prime is 85511711. The next prime is 85511731. The reversal of 85511729 is 92711558.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92711558 = 2 ⋅46355779.

It can be written as a sum of positive squares in 2 ways, for example, as 14615329 + 70896400 = 3823^2 + 8420^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85511729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85511692 and 85511701.

It is not an unprimeable number, because it can be changed into a prime (85511929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12464 + ... + 18065.

It is an arithmetic number, because the mean of its divisors is an integer number (21386265).

Almost surely, 2^85511729 is an apocalyptic number.

It is an amenable number.

85511729 is a deficient number, since it is larger than the sum of its proper divisors (33331).

85511729 is a wasteful number, since it uses less digits than its factorization.

85511729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33330.

The product of its digits is 25200, while the sum is 38.

The square root of 85511729 is about 9247.2552143866. The cubic root of 85511729 is about 440.5635495948.

The spelling of 85511729 in words is "eighty-five million, five hundred eleven thousand, seven hundred twenty-nine".