81181180 has 12 divisors (see below), whose sum is σ = 170480520. Its totient is φ = 32472464.

The previous prime is 81181159. The next prime is 81181193. The reversal of 81181180 is 8118118.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2029510 + ... + 2029549.

It is an arithmetic number, because the mean of its divisors is an integer number (14206710).

Almost surely, 2^81181180 is an apocalyptic number.

It is an amenable number.

81181180 is an abundant number, since it is smaller than the sum of its proper divisors (89299340).

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

81181180 is a wasteful number, since it uses less digits than its factorization.

81181180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4059068 (or 4059066 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 28.

The square root of 81181180 is about 9010.0599332080. The cubic root of 81181180 is about 432.9972318199.

Adding to 81181180 its reverse (8118118), we get a palindrome (89299298).

The spelling of 81181180 in words is "eighty-one million, one hundred eighty-one thousand, one hundred eighty".