18021440805 has 32 divisors (see below), whose sum is σ = 29473217280. Its totient is φ = 9399636480.

The previous prime is 18021440761. The next prime is 18021440821. The reversal of 18021440805 is 50804412081.

It is not a de Polignac number, because 18021440805 - 2⁹ = 18021440293 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 210801 + ... + 283689.

It is an arithmetic number, because the mean of its divisors is an integer number (921038040).

Almost surely, 2^18021440805 is an apocalyptic number.

18021440805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18021440805 is a deficient number, since it is larger than the sum of its proper divisors (11451776475).

18021440805 is a wasteful number, since it uses less digits than its factorization.

18021440805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73261.

The product of its (nonzero) digits is 10240, while the sum is 33.

Adding to 18021440805 its reverse (50804412081), we get a palindrome (68825852886).

The spelling of 18021440805 in words is "eighteen billion, twenty-one million, four hundred forty thousand, eight hundred five".