18180520281863 has 4 divisors (see below), whose sum is σ = 18488664693480. Its totient is φ = 17872375870248.

The previous prime is 18180520281853. The next prime is 18180520281997. The reversal of 18180520281863 is 36818202508181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18180520281863 - 2³⁶ = 18111800805127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18180520281853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154072205720 + ... + 154072205837.

It is an arithmetic number, because the mean of its divisors is an integer number (4622166173370).

Almost surely, 2^{18180520281863} is an apocalyptic number.

18180520281863 is a deficient number, since it is larger than the sum of its proper divisors (308144411617).

18180520281863 is an equidigital number, since it uses as much as digits as its factorization.

18180520281863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308144411616.

The product of its (nonzero) digits is 1474560, while the sum is 53.

The spelling of 18180520281863 in words is "eighteen trillion, one hundred eighty billion, five hundred twenty million, two hundred eighty-one thousand, eight hundred sixty-three".