18538873 has 2 divisors, whose sum is σ = 18538874. Its totient is φ = 18538872.

The previous prime is 18538843. The next prime is 18538901. The reversal of 18538873 is 37883581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18003049 + 535824 = 4243^2 + 732^2 .

It is a cyclic number.

It is not a de Polignac number, because 18538873 - 2⁵ = 18538841 is a prime.

It is a super-2 number, since 2×18538873² = 687379624220258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18538843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9269436 + 9269437.

It is an arithmetic number, because the mean of its divisors is an integer number (9269437).

Almost surely, 2^18538873 is an apocalyptic number.

It is an amenable number.

18538873 is a deficient number, since it is larger than the sum of its proper divisors (1).

18538873 is an equidigital number, since it uses as much as digits as its factorization.

18538873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 43.

The square root of 18538873 is about 4305.6791566488. The cubic root of 18538873 is about 264.6637386782.

The spelling of 18538873 in words is "eighteen million, five hundred thirty-eight thousand, eight hundred seventy-three".