18020405 has 16 divisors (see below), whose sum is σ = 23514624. Its totient is φ = 13177920.

The previous prime is 18020399. The next prime is 18020413. The reversal of 18020405 is 50402081.

It is not a de Polignac number, because 18020405 - 2⁴ = 18020389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5660 + ... + 8250.

It is an arithmetic number, because the mean of its divisors is an integer number (1469664).

Almost surely, 2^18020405 is an apocalyptic number.

It is an amenable number.

18020405 is a deficient number, since it is larger than the sum of its proper divisors (5494219).

18020405 is a wasteful number, since it uses less digits than its factorization.

18020405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2716.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 18020405 is about 4245.0447583035. The cubic root of 18020405 is about 262.1731320760.

Adding to 18020405 its reverse (50402081), we get a palindrome (68422486).

The spelling of 18020405 in words is "eighteen million, twenty thousand, four hundred five".