82728281 has 4 divisors (see below), whose sum is σ = 83083572. Its totient is φ = 82372992.

The previous prime is 82728187. The next prime is 82728301. The reversal of 82728281 is 18282728.

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 50055625 + 32672656 = 7075^2 + 5716^2 .

It is a cyclic number.

It is not a de Polignac number, because 82728281 - 2¹⁴ = 82711897 is a prime.

It is a super-2 number, since 2×82728281² = 13687936954429922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82721281) 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, 177296 + ... + 177761.

It is an arithmetic number, because the mean of its divisors is an integer number (20770893).

Almost surely, 2^82728281 is an apocalyptic number.

It is an amenable number.

82728281 is a deficient number, since it is larger than the sum of its proper divisors (355291).

82728281 is a wasteful number, since it uses less digits than its factorization.

82728281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355290.

The product of its digits is 28672, while the sum is 38.

The square root of 82728281 is about 9095.5088367831. The cubic root of 82728281 is about 435.7305397399.

The spelling of 82728281 in words is "eighty-two million, seven hundred twenty-eight thousand, two hundred eighty-one".