18812521 has 16 divisors (see below), whose sum is σ = 23632000. Its totient is φ = 14881104.

The previous prime is 18812513. The next prime is 18812533. The reversal of 18812521 is 12521881.

It is not a de Polignac number, because 18812521 - 2³ = 18812513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18812521.

It is not an unprimeable number, because it can be changed into a prime (18812581) 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 15 ways as a sum of consecutive naturals, for example, 2350 + ... + 6568.

It is an arithmetic number, because the mean of its divisors is an integer number (1477000).

Almost surely, 2^18812521 is an apocalyptic number.

It is an amenable number.

18812521 is a deficient number, since it is larger than the sum of its proper divisors (4819479).

18812521 is an equidigital number, since it uses as much as digits as its factorization.

18812521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4253 (or 4239 counting only the distinct ones).

The product of its digits is 1280, while the sum is 28.

The square root of 18812521 is about 4337.3403140634. The cubic root of 18812521 is about 265.9595968182.

The spelling of 18812521 in words is "eighteen million, eight hundred twelve thousand, five hundred twenty-one".