18587081 has 2 divisors, whose sum is σ = 18587082. Its totient is φ = 18587080.

The previous prime is 18587039. The next prime is 18587083. The reversal of 18587081 is 18078581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18567481 + 19600 = 4309^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 18587081 - 2⁶ = 18587017 is a prime.

It is a super-2 number, since 2×18587081² = 690959160201122, which contains 22 as substring.

Together with 18587083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18587083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9293540 + 9293541.

It is an arithmetic number, because the mean of its divisors is an integer number (9293541).

Almost surely, 2^18587081 is an apocalyptic number.

It is an amenable number.

18587081 is a deficient number, since it is larger than the sum of its proper divisors (1).

18587081 is an equidigital number, since it uses as much as digits as its factorization.

18587081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17920, while the sum is 38.

The square root of 18587081 is about 4311.2737097058. The cubic root of 18587081 is about 264.8929483350.

The spelling of 18587081 in words is "eighteen million, five hundred eighty-seven thousand, eighty-one".