18343521 has 12 divisors (see below), whose sum is σ = 30281472. Its totient is φ = 10481976.

The previous prime is 18343517. The next prime is 18343529. The reversal of 18343521 is 12534381.

It is a happy number.

It is not a de Polignac number, because 18343521 - 2² = 18343517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18343529) 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 11 ways as a sum of consecutive naturals, for example, 145521 + ... + 145646.

It is an arithmetic number, because the mean of its divisors is an integer number (2523456).

Almost surely, 2^18343521 is an apocalyptic number.

It is an amenable number.

18343521 is a deficient number, since it is larger than the sum of its proper divisors (11937951).

18343521 is a wasteful number, since it uses less digits than its factorization.

18343521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291180 (or 291177 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 18343521 is about 4282.9336908245. The cubic root of 18343521 is about 263.7308293007.

The spelling of 18343521 in words is "eighteen million, three hundred forty-three thousand, five hundred twenty-one".