18342521 has 4 divisors (see below), whose sum is σ = 18361344. Its totient is φ = 18323700.

The previous prime is 18342503. The next prime is 18342547. The reversal of 18342521 is 12524381.

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: 12524381 = 257 ⋅48733.

It is a cyclic number.

It is not a de Polignac number, because 18342521 - 2¹⁰ = 18341497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18348521) 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, 7865 + ... + 9926.

It is an arithmetic number, because the mean of its divisors is an integer number (4590336).

Almost surely, 2^18342521 is an apocalyptic number.

It is an amenable number.

18342521 is a deficient number, since it is larger than the sum of its proper divisors (18823).

18342521 is a wasteful number, since it uses less digits than its factorization.

18342521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18822.

The product of its digits is 1920, while the sum is 26.

The square root of 18342521 is about 4282.8169468237. The cubic root of 18342521 is about 263.7260367708.

The spelling of 18342521 in words is "eighteen million, three hundred forty-two thousand, five hundred twenty-one".