81118280 has 32 divisors (see below), whose sum is σ = 182987640. Its totient is φ = 32363520.

The previous prime is 81118267. The next prime is 81118283. The reversal of 81118280 is 8281118.

It can be written as a sum of positive squares in 4 ways, for example, as 19307236 + 61811044 = 4394^2 + 7862^2 .

It is not an unprimeable number, because it can be changed into a prime (81118283) 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, 14432 + ... + 19248.

Almost surely, 2^81118280 is an apocalyptic number.

It is an amenable number.

81118280 is an abundant number, since it is smaller than the sum of its proper divisors (101869360).

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

81118280 is a wasteful number, since it uses less digits than its factorization.

81118280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5249 (or 5245 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 81118280 is about 9006.5687139998. The cubic root of 81118280 is about 432.8853727124.

Adding to 81118280 its reverse (8281118), we get a palindrome (89399398).

It can be divided in two parts, 811 and 18280, that added together give a palindrome (19091).

The spelling of 81118280 in words is "eighty-one million, one hundred eighteen thousand, two hundred eighty".