17968409 has 4 divisors (see below), whose sum is σ = 18013620. Its totient is φ = 17923200.

The previous prime is 17968399. The next prime is 17968411. The reversal of 17968409 is 90486971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90486971 = 17 ⋅5322763.

It can be written as a sum of positive squares in 2 ways, for example, as 16000000 + 1968409 = 4000^2 + 1403^2 .

It is a cyclic number.

It is not a de Polignac number, because 17968409 - 2¹² = 17964313 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 17968409.

It is not an unprimeable number, because it can be changed into a prime (17968459) 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, 22004 + ... + 22805.

It is an arithmetic number, because the mean of its divisors is an integer number (4503405).

Almost surely, 2^17968409 is an apocalyptic number.

It is an amenable number.

17968409 is a deficient number, since it is larger than the sum of its proper divisors (45211).

17968409 is an equidigital number, since it uses as much as digits as its factorization.

17968409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45210.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 17968409 is about 4238.9160170968. The cubic root of 17968409 is about 261.9207314145.

The spelling of 17968409 in words is "seventeen million, nine hundred sixty-eight thousand, four hundred nine".