18427521 has 16 divisors (see below), whose sum is σ = 28734464. Its totient is φ = 10284624.

The previous prime is 18427501. The next prime is 18427523. The reversal of 18427521 is 12572481.

It is not a de Polignac number, because 18427521 - 2¹³ = 18419329 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18427523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9301 + ... + 11106.

It is an arithmetic number, because the mean of its divisors is an integer number (1795904).

Almost surely, 2^18427521 is an apocalyptic number.

It is an amenable number.

18427521 is a deficient number, since it is larger than the sum of its proper divisors (10306943).

18427521 is a wasteful number, since it uses less digits than its factorization.

18427521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20460.

The product of its digits is 4480, while the sum is 30.

The square root of 18427521 is about 4292.7288523735. The cubic root of 18427521 is about 264.1327815750.

The spelling of 18427521 in words is "eighteen million, four hundred twenty-seven thousand, five hundred twenty-one".