18012881585 has 8 divisors (see below), whose sum is σ = 21619291560. Its totient is φ = 14407749504.

The previous prime is 18012881567. The next prime is 18012881597. The reversal of 18012881585 is 58518821081.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9655813696 + 8357067889 = 98264^2 + 91417^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18012881585 - 2⁶ = 18012881521 is a prime.

It is a super-2 number, since 2×18012881585² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 288182 + ... + 345071.

It is an arithmetic number, because the mean of its divisors is an integer number (2702411445).

Almost surely, 2^18012881585 is an apocalyptic number.

It is an amenable number.

18012881585 is a deficient number, since it is larger than the sum of its proper divisors (3606409975).

18012881585 is an equidigital number, since it uses as much as digits as its factorization.

18012881585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638947.

The product of its (nonzero) digits is 204800, while the sum is 47.

The spelling of 18012881585 in words is "eighteen billion, twelve million, eight hundred eighty-one thousand, five hundred eighty-five".