16242409 has 4 divisors (see below), whose sum is σ = 16508740. Its totient is φ = 15976080.

The previous prime is 16242403. The next prime is 16242431. The reversal of 16242409 is 90424261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90424261 = 211 ⋅428551.

It can be written as a sum of positive squares in 2 ways, for example, as 3080025 + 13162384 = 1755^2 + 3628^2 .

It is a cyclic number.

It is not a de Polignac number, because 16242409 - 2⁵ = 16242377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16242403) 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, 133074 + ... + 133195.

It is an arithmetic number, because the mean of its divisors is an integer number (4127185).

Almost surely, 2^16242409 is an apocalyptic number.

It is an amenable number.

16242409 is a deficient number, since it is larger than the sum of its proper divisors (266331).

16242409 is an equidigital number, since it uses as much as digits as its factorization.

16242409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266330.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 16242409 is about 4030.1872164950. The cubic root of 16242409 is about 253.2504043350.

The spelling of 16242409 in words is "sixteen million, two hundred forty-two thousand, four hundred nine".