18458521 has 4 divisors (see below), whose sum is σ = 18474192. Its totient is φ = 18442852.

The previous prime is 18458507. The next prime is 18458533. The reversal of 18458521 is 12585481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12585481 = 67 ⋅187843.

It is a cyclic number.

It is not a de Polignac number, because 18458521 - 2¹³ = 18450329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18458551) 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, 5911 + ... + 8476.

It is an arithmetic number, because the mean of its divisors is an integer number (4618548).

Almost surely, 2^18458521 is an apocalyptic number.

It is an amenable number.

18458521 is a deficient number, since it is larger than the sum of its proper divisors (15671).

18458521 is a wasteful number, since it uses less digits than its factorization.

18458521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15670.

The product of its digits is 12800, while the sum is 34.

The square root of 18458521 is about 4296.3380919104. The cubic root of 18458521 is about 264.2808125008.

The spelling of 18458521 in words is "eighteen million, four hundred fifty-eight thousand, five hundred twenty-one".