81816108 has 24 divisors (see below), whose sum is σ = 208259520. Its totient is φ = 24792720.

The previous prime is 81816107. The next prime is 81816157. The reversal of 81816108 is 80161818.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81816103) 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 7 ways as a sum of consecutive naturals, for example, 309778 + ... + 310041.

It is an arithmetic number, because the mean of its divisors is an integer number (8677480).

Almost surely, 2^81816108 is an apocalyptic number.

It is an amenable number.

81816108 is an abundant number, since it is smaller than the sum of its proper divisors (126443412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81816108 is a wasteful number, since it uses less digits than its factorization.

81816108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619837 (or 619835 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 33.

The square root of 81816108 is about 9045.2257019933. The cubic root of 81816108 is about 434.1231431514.

The spelling of 81816108 in words is "eighty-one million, eight hundred sixteen thousand, one hundred eight".