18215423 has 4 divisors (see below), whose sum is σ = 18227568. Its totient is φ = 18203280.

The previous prime is 18215387. The next prime is 18215437. The reversal of 18215423 is 32451281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32451281 = 107 ⋅303283.

It is a cyclic number.

It is not a de Polignac number, because 18215423 - 2¹⁸ = 17953279 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18215392 and 18215401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18215443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3443 + ... + 6948.

It is an arithmetic number, because the mean of its divisors is an integer number (4556892).

Almost surely, 2^18215423 is an apocalyptic number.

18215423 is a deficient number, since it is larger than the sum of its proper divisors (12145).

18215423 is a wasteful number, since it uses less digits than its factorization.

18215423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12144.

The product of its digits is 1920, while the sum is 26.

The square root of 18215423 is about 4267.9530222344. The cubic root of 18215423 is about 263.1154923660.

The spelling of 18215423 in words is "eighteen million, two hundred fifteen thousand, four hundred twenty-three".