18520389 has 12 divisors (see below), whose sum is σ = 26842816. Its totient is φ = 12304872.

The previous prime is 18520379. The next prime is 18520391. The reversal of 18520389 is 98302581.

It is not a de Polignac number, because 18520389 - 2⁷ = 18520261 is a prime.

It is a super-2 number, since 2×18520389² = 686009617422642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18520339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 589 + ... + 6114.

Almost surely, 2^18520389 is an apocalyptic number.

It is an amenable number.

18520389 is a deficient number, since it is larger than the sum of its proper divisors (8322427).

18520389 is a wasteful number, since it uses less digits than its factorization.

18520389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7016 (or 7013 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 18520389 is about 4303.5321539405. The cubic root of 18520389 is about 264.5757493076.

The spelling of 18520389 in words is "eighteen million, five hundred twenty thousand, three hundred eighty-nine".