18019471 has 4 divisors (see below), whose sum is σ = 18402912. Its totient is φ = 17636032.

The previous prime is 18019457. The next prime is 18019489. The reversal of 18019471 is 17491081.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18019471 - 2⁷ = 18019343 is a prime.

It is a super-3 number, since 3×18019471³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18019271) 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 3 ways as a sum of consecutive naturals, for example, 191650 + ... + 191743.

It is an arithmetic number, because the mean of its divisors is an integer number (4600728).

Almost surely, 2^18019471 is an apocalyptic number.

18019471 is a deficient number, since it is larger than the sum of its proper divisors (383441).

18019471 is an equidigital number, since it uses as much as digits as its factorization.

18019471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383440.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 18019471 is about 4244.9347462594. The cubic root of 18019471 is about 262.1686025083.

The spelling of 18019471 in words is "eighteen million, nineteen thousand, four hundred seventy-one".