16240409 has 4 divisors (see below), whose sum is σ = 16276404. Its totient is φ = 16204416.

The previous prime is 16240403. The next prime is 16240417. The reversal of 16240409 is 90404261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13690000 + 2550409 = 3700^2 + 1597^2 .

It is a cyclic number.

It is not a de Polignac number, because 16240409 - 2⁸ = 16240153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16240403) 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, 17312 + ... + 18225.

It is an arithmetic number, because the mean of its divisors is an integer number (4069101).

Almost surely, 2^16240409 is an apocalyptic number.

It is an amenable number.

16240409 is a deficient number, since it is larger than the sum of its proper divisors (35995).

16240409 is an equidigital number, since it uses as much as digits as its factorization.

16240409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35994.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 16240409 is about 4029.9390814254. The cubic root of 16240409 is about 253.2400092924.

The spelling of 16240409 in words is "sixteen million, two hundred forty thousand, four hundred nine".