81875618 has 24 divisors (see below), whose sum is σ = 135770124. Its totient is φ = 37002240.

The previous prime is 81875611. The next prime is 81875641. The reversal of 81875618 is 81657818.

It can be written as a sum of positive squares in 2 ways, for example, as 66797929 + 15077689 = 8173^2 + 3883^2 .

It is not an unprimeable number, because it can be changed into a prime (81875611) 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 in 11 ways as a sum of consecutive naturals, for example, 45830 + ... + 47582.

Almost surely, 2^81875618 is an apocalyptic number.

81875618 is a deficient number, since it is larger than the sum of its proper divisors (53894506).

81875618 is a wasteful number, since it uses less digits than its factorization.

81875618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1970 (or 1959 counting only the distinct ones).

The product of its digits is 107520, while the sum is 44.

The square root of 81875618 is about 9048.5146847425. The cubic root of 81875618 is about 434.2283726622.

The spelling of 81875618 in words is "eighty-one million, eight hundred seventy-five thousand, six hundred eighteen".