18130621 has 2 divisors, whose sum is σ = 18130622. Its totient is φ = 18130620.

The previous prime is 18130591. The next prime is 18130627. The reversal of 18130621 is 12603181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 68121 = 4250^2 + 261^2 .

It is an emirp because it is prime and its reverse (12603181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18130621 - 2⁷ = 18130493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18130592 and 18130601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18130627) 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, 9065310 + 9065311.

It is an arithmetic number, because the mean of its divisors is an integer number (9065311).

Almost surely, 2^18130621 is an apocalyptic number.

It is an amenable number.

18130621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18130621 is an equidigital number, since it uses as much as digits as its factorization.

18130621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 18130621 is about 4258.0066932780. The cubic root of 18130621 is about 262.7065452249.

The spelling of 18130621 in words is "eighteen million, one hundred thirty thousand, six hundred twenty-one".