18420415 has 16 divisors (see below), whose sum is σ = 24258528. Its totient is φ = 13343616.

The previous prime is 18420407. The next prime is 18420421. The reversal of 18420415 is 51402481.

It is not a de Polignac number, because 18420415 - 2³ = 18420407 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18420415.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 772 + ... + 6118.

It is an arithmetic number, because the mean of its divisors is an integer number (1516158).

Almost surely, 2^18420415 is an apocalyptic number.

18420415 is a deficient number, since it is larger than the sum of its proper divisors (5838113).

18420415 is a wasteful number, since it uses less digits than its factorization.

18420415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5418.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 18420415 is about 4291.9010939210. The cubic root of 18420415 is about 264.0988256808.

Adding to 18420415 its reverse (51402481), we get a palindrome (69822896).

The spelling of 18420415 in words is "eighteen million, four hundred twenty thousand, four hundred fifteen".