18081181540 has 12 divisors (see below), whose sum is σ = 37970481276. Its totient is φ = 7232472608.

The previous prime is 18081181529. The next prime is 18081181541. The reversal of 18081181540 is 4518118081.

It can be written as a sum of positive squares in 2 ways, for example, as 11880564004 + 6200617536 = 108998^2 + 78744^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18081181540.

It is not an unprimeable number, because it can be changed into a prime (18081181541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452029519 + ... + 452029558.

It is an arithmetic number, because the mean of its divisors is an integer number (3164206773).

Almost surely, 2^18081181540 is an apocalyptic number.

18081181540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18081181540 is an abundant number, since it is smaller than the sum of its proper divisors (19889299736).

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

18081181540 is a wasteful number, since it uses less digits than its factorization.

18081181540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904059086 (or 904059084 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 37.

The spelling of 18081181540 in words is "eighteen billion, eighty-one million, one hundred eighty-one thousand, five hundred forty".