82781317 has 4 divisors (see below), whose sum is σ = 83601036. Its totient is φ = 81961600.

The previous prime is 82781297. The next prime is 82781323. The reversal of 82781317 is 71318728.

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 80838081 + 1943236 = 8991^2 + 1394^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82781317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82781717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409708 + ... + 409909.

It is an arithmetic number, because the mean of its divisors is an integer number (20900259).

Almost surely, 2^82781317 is an apocalyptic number.

It is an amenable number.

82781317 is a deficient number, since it is larger than the sum of its proper divisors (819719).

82781317 is a wasteful number, since it uses less digits than its factorization.

82781317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819718.

The product of its digits is 18816, while the sum is 37.

The square root of 82781317 is about 9098.4238744961. The cubic root of 82781317 is about 435.8236335325.

The spelling of 82781317 in words is "eighty-two million, seven hundred eighty-one thousand, three hundred seventeen".