18520693 has 2 divisors, whose sum is σ = 18520694. Its totient is φ = 18520692.

The previous prime is 18520613. The next prime is 18520717. The reversal of 18520693 is 39602581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9622404 + 8898289 = 3102^2 + 2983^2 .

It is an emirp because it is prime and its reverse (39602581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18520693 - 2⁹ = 18520181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18520613) 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, 9260346 + 9260347.

It is an arithmetic number, because the mean of its divisors is an integer number (9260347).

Almost surely, 2^18520693 is an apocalyptic number.

It is an amenable number.

18520693 is a deficient number, since it is larger than the sum of its proper divisors (1).

18520693 is an equidigital number, since it uses as much as digits as its factorization.

18520693 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 18520693 is about 4303.5674736200. The cubic root of 18520693 is about 264.5771969120.

The spelling of 18520693 in words is "eighteen million, five hundred twenty thousand, six hundred ninety-three".