81181876 has 24 divisors (see below), whose sum is σ = 145313280. Its totient is φ = 39672000.

The previous prime is 81181853. The next prime is 81181883. The reversal of 81181876 is 67818118.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44176 + ... + 45976.

It is an arithmetic number, because the mean of its divisors is an integer number (6054720).

Almost surely, 2^81181876 is an apocalyptic number.

It is an amenable number.

81181876 is a deficient number, since it is larger than the sum of its proper divisors (64131404).

81181876 is a wasteful number, since it uses less digits than its factorization.

81181876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2055 (or 2053 counting only the distinct ones).

The product of its digits is 21504, while the sum is 40.

The square root of 81181876 is about 9010.0985566197. The cubic root of 81181876 is about 432.9984692381.

The spelling of 81181876 in words is "eighty-one million, one hundred eighty-one thousand, eight hundred seventy-six".