18720513 has 12 divisors (see below), whose sum is σ = 30903808. Its totient is φ = 10697400.

The previous prime is 18720467. The next prime is 18720539. The reversal of 18720513 is 31502781.

It is not a de Polignac number, because 18720513 - 2⁸ = 18720257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18720563) 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, 148513 + ... + 148638.

Almost surely, 2^18720513 is an apocalyptic number.

It is an amenable number.

18720513 is a deficient number, since it is larger than the sum of its proper divisors (12183295).

18720513 is a wasteful number, since it uses less digits than its factorization.

18720513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297164 (or 297161 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 18720513 is about 4326.7208137341. The cubic root of 18720513 is about 265.5253042796.

The spelling of 18720513 in words is "eighteen million, seven hundred twenty thousand, five hundred thirteen".