18725513 has 4 divisors (see below), whose sum is σ = 18738180. Its totient is φ = 18712848.

The previous prime is 18725489. The next prime is 18725527. The reversal of 18725513 is 31552781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31552781 = 13 ⋅2427137.

It can be written as a sum of positive squares in 2 ways, for example, as 7382089 + 11343424 = 2717^2 + 3368^2 .

It is a cyclic number.

It is not a de Polignac number, because 18725513 - 2¹⁸ = 18463369 is a prime.

It is a super-2 number, since 2×18725513² = 701289674226338, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18725513.

It is not an unprimeable number, because it can be changed into a prime (18725563) 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 in 3 ways as a sum of consecutive naturals, for example, 3770 + ... + 7187.

It is an arithmetic number, because the mean of its divisors is an integer number (4684545).

Almost surely, 2^18725513 is an apocalyptic number.

It is an amenable number.

18725513 is a deficient number, since it is larger than the sum of its proper divisors (12667).

18725513 is a wasteful number, since it uses less digits than its factorization.

18725513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12666.

The product of its digits is 8400, while the sum is 32.

The square root of 18725513 is about 4327.2985799457. The cubic root of 18725513 is about 265.5489416009.

The spelling of 18725513 in words is "eighteen million, seven hundred twenty-five thousand, five hundred thirteen".