18721075 has 18 divisors (see below), whose sum is σ = 23902116. Its totient is φ = 14545440.

The previous prime is 18721033. The next prime is 18721091. The reversal of 18721075 is 57012781.

It is a happy number.

It is not a de Polignac number, because 18721075 - 2⁹ = 18720563 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 33952 + ... + 34498.

Almost surely, 2^18721075 is an apocalyptic number.

18721075 is a deficient number, since it is larger than the sum of its proper divisors (5181041).

18721075 is an equidigital number, since it uses as much as digits as its factorization.

18721075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631 (or 589 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 18721075 is about 4326.7857585048. The cubic root of 18721075 is about 265.5279613244.

The spelling of 18721075 in words is "eighteen million, seven hundred twenty-one thousand, seventy-five".