18473521 has 8 divisors (see below), whose sum is σ = 20533824. Its totient is φ = 16476720.

The previous prime is 18473513. The next prime is 18473537. The reversal of 18473521 is 12537481.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18473521 - 2³ = 18473513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18473501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15261 + ... + 16426.

It is an arithmetic number, because the mean of its divisors is an integer number (2566728).

Almost surely, 2^18473521 is an apocalyptic number.

18473521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18473521 is a deficient number, since it is larger than the sum of its proper divisors (2060303).

18473521 is a wasteful number, since it uses less digits than its factorization.

18473521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31751.

The product of its digits is 6720, while the sum is 31.

The square root of 18473521 is about 4298.0834100794. The cubic root of 18473521 is about 264.3523808722.

The spelling of 18473521 in words is "eighteen million, four hundred seventy-three thousand, five hundred twenty-one".