817542085 has 4 divisors (see below), whose sum is σ = 981050508. Its totient is φ = 654033664.

The previous prime is 817542073. The next prime is 817542097. The reversal of 817542085 is 580245718.

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

It is an interprime number because it is at equal distance from previous prime (817542073) and next prime (817542097).

It can be written as a sum of positive squares in 2 ways, for example, as 335695684 + 481846401 = 18322^2 + 21951^2 .

It is a cyclic number.

It is not a de Polignac number, because 817542085 - 2⁷ = 817541957 is a prime.

It is a super-2 number, since 2×817542085² = 1336750121492294450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 81754204 + ... + 81754213.

It is an arithmetic number, because the mean of its divisors is an integer number (245262627).

Almost surely, 2^817542085 is an apocalyptic number.

It is an amenable number.

817542085 is a deficient number, since it is larger than the sum of its proper divisors (163508423).

817542085 is a wasteful number, since it uses less digits than its factorization.

817542085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163508422.

The product of its (nonzero) digits is 89600, while the sum is 40.

The square root of 817542085 is about 28592.6928602397. The cubic root of 817542085 is about 935.0540294972.

The spelling of 817542085 in words is "eight hundred seventeen million, five hundred forty-two thousand, eighty-five".