81815282 has 8 divisors (see below), whose sum is σ = 123346476. Its totient is φ = 40699792.

The previous prime is 81815281. The next prime is 81815309. The reversal of 81815282 is 28251818.

It can be written as a sum of positive squares in 2 ways, for example, as 69572281 + 12243001 = 8341^2 + 3499^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81815281) 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, 103433 + ... + 104220.

Almost surely, 2^81815282 is an apocalyptic number.

81815282 is a deficient number, since it is larger than the sum of its proper divisors (41531194).

81815282 is a wasteful number, since it uses less digits than its factorization.

81815282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207852.

The product of its digits is 10240, while the sum is 35.

The square root of 81815282 is about 9045.1800424314. The cubic root of 81815282 is about 434.1216822047.

The spelling of 81815282 in words is "eighty-one million, eight hundred fifteen thousand, two hundred eighty-two".