81186118 has 32 divisors (see below), whose sum is σ = 140597856. Its totient is φ = 34825728.

The previous prime is 81186097. The next prime is 81186121. The reversal of 81186118 is 81168118.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35580 + ... + 37792.

It is an arithmetic number, because the mean of its divisors is an integer number (4393683).

Almost surely, 2^81186118 is an apocalyptic number.

81186118 is a deficient number, since it is larger than the sum of its proper divisors (59411738).

81186118 is a wasteful number, since it uses less digits than its factorization.

81186118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2328.

The product of its digits is 3072, while the sum is 34.

The square root of 81186118 is about 9010.3339560751. Note that the first 3 decimals coincide. The cubic root of 81186118 is about 433.0060109359.

The spelling of 81186118 in words is "eighty-one million, one hundred eighty-six thousand, one hundred eighteen".