18423505 has 4 divisors (see below), whose sum is σ = 22108212. Its totient is φ = 14738800.

The previous prime is 18423491. The next prime is 18423533. The reversal of 18423505 is 50532481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50532481 = 359 ⋅140759.

It can be written as a sum of positive squares in 2 ways, for example, as 2455489 + 15968016 = 1567^2 + 3996^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18423505 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1842346 + ... + 1842355.

It is an arithmetic number, because the mean of its divisors is an integer number (5527053).

Almost surely, 2^18423505 is an apocalyptic number.

It is an amenable number.

18423505 is a deficient number, since it is larger than the sum of its proper divisors (3684707).

18423505 is an equidigital number, since it uses as much as digits as its factorization.

18423505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3684706.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 18423505 is about 4292.2610591622. The cubic root of 18423505 is about 264.1135922635.

Adding to 18423505 its reverse (50532481), we get a palindrome (68955986).

The spelling of 18423505 in words is "eighteen million, four hundred twenty-three thousand, five hundred five".