18466409 has 4 divisors (see below), whose sum is σ = 19886916. Its totient is φ = 17045904.

The previous prime is 18466397. The next prime is 18466411. The reversal of 18466409 is 90466481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90466481 = 7 ⋅12923783.

It can be written as a sum of positive squares in 2 ways, for example, as 6390784 + 12075625 = 2528^2 + 3475^2 .

It is a cyclic number.

It is not a de Polignac number, because 18466409 - 2²⁰ = 17417833 is a prime.

It is a super-2 number, since 2×18466409² = 682016522710562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18466429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 710234 + ... + 710259.

It is an arithmetic number, because the mean of its divisors is an integer number (4971729).

Almost surely, 2^18466409 is an apocalyptic number.

It is an amenable number.

18466409 is a deficient number, since it is larger than the sum of its proper divisors (1420507).

18466409 is a wasteful number, since it uses less digits than its factorization.

18466409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420506.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 18466409 is about 4297.2559849281. The cubic root of 18466409 is about 264.3184527533.

The spelling of 18466409 in words is "eighteen million, four hundred sixty-six thousand, four hundred nine".