81813752 has 8 divisors (see below), whose sum is σ = 153400800. Its totient is φ = 40906872.

The previous prime is 81813731. The next prime is 81813761. The reversal of 81813752 is 25731818.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

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, 5113352 + ... + 5113367.

It is an arithmetic number, because the mean of its divisors is an integer number (19175100).

Almost surely, 2^81813752 is an apocalyptic number.

It is an amenable number.

81813752 is a deficient number, since it is larger than the sum of its proper divisors (71587048).

81813752 is a wasteful number, since it uses less digits than its factorization.

81813752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10226725 (or 10226721 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 81813752 is about 9045.0954666051. The cubic root of 81813752 is about 434.1189760668.

The spelling of 81813752 in words is "eighty-one million, eight hundred thirteen thousand, seven hundred fifty-two".