81856282 has 4 divisors (see below), whose sum is σ = 122784426. Its totient is φ = 40928140.

The previous prime is 81856277. The next prime is 81856283. The reversal of 81856282 is 28265818.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 56565441 + 25290841 = 7521^2 + 5029^2 .

It is not an unprimeable number, because it can be changed into a prime (81856283) 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 as a sum of consecutive naturals, namely, 20464069 + ... + 20464072.

Almost surely, 2^81856282 is an apocalyptic number.

81856282 is a deficient number, since it is larger than the sum of its proper divisors (40928144).

81856282 is a wasteful number, since it uses less digits than its factorization.

81856282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40928143.

The product of its digits is 61440, while the sum is 40.

The square root of 81856282 is about 9047.4461589998. The cubic root of 81856282 is about 434.1941870643.

The spelling of 81856282 in words is "eighty-one million, eight hundred fifty-six thousand, two hundred eighty-two".