18530881 has 2 divisors, whose sum is σ = 18530882. Its totient is φ = 18530880.

The previous prime is 18530879. The next prime is 18530887. The reversal of 18530881 is 18803581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10995856 + 7535025 = 3316^2 + 2745^2 .

It is a cyclic number.

It is not a de Polignac number, because 18530881 - 2¹ = 18530879 is a prime.

It is a super-2 number, since 2×18530881² = 686787101272322, which contains 22 as substring.

Together with 18530879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18530887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9265440 + 9265441.

It is an arithmetic number, because the mean of its divisors is an integer number (9265441).

Almost surely, 2^18530881 is an apocalyptic number.

It is an amenable number.

18530881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18530881 is an equidigital number, since it uses as much as digits as its factorization.

18530881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 34.

The square root of 18530881 is about 4304.7509800220. The cubic root of 18530881 is about 264.6257015473.

The spelling of 18530881 in words is "eighteen million, five hundred thirty thousand, eight hundred eighty-one".