18256513 has 4 divisors (see below), whose sum is σ = 19916208. Its totient is φ = 16596820.

The previous prime is 18256499. The next prime is 18256529. The reversal of 18256513 is 31565281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18256513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18256013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 829831 + ... + 829852.

It is an arithmetic number, because the mean of its divisors is an integer number (4979052).

Almost surely, 2^18256513 is an apocalyptic number.

It is an amenable number.

18256513 is a deficient number, since it is larger than the sum of its proper divisors (1659695).

18256513 is a wasteful number, since it uses less digits than its factorization.

18256513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659694.

The product of its digits is 7200, while the sum is 31.

The square root of 18256513 is about 4272.7640936518. The cubic root of 18256513 is about 263.3131874064.

It can be divided in two parts, 18256 and 513, that added together give a square (18769 = 137²).

The spelling of 18256513 in words is "eighteen million, two hundred fifty-six thousand, five hundred thirteen".