18214409 has 4 divisors (see below), whose sum is σ = 18272916. Its totient is φ = 18155904.

The previous prime is 18214393. The next prime is 18214439. The reversal of 18214409 is 90441281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90441281 = 7 ⋅12920183.

It can be written as a sum of positive squares in 2 ways, for example, as 3222025 + 14992384 = 1795^2 + 3872^2 .

It is a cyclic number.

It is not a de Polignac number, because 18214409 - 2⁴ = 18214393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18214439) 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, 28784 + ... + 29409.

It is an arithmetic number, because the mean of its divisors is an integer number (4568229).

Almost surely, 2^18214409 is an apocalyptic number.

It is an amenable number.

18214409 is a deficient number, since it is larger than the sum of its proper divisors (58507).

18214409 is an equidigital number, since it uses as much as digits as its factorization.

18214409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58506.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 18214409 is about 4267.8342282708. The cubic root of 18214409 is about 263.1106099822.

The spelling of 18214409 in words is "eighteen million, two hundred fourteen thousand, four hundred nine".