19668505 has 16 divisors (see below), whose sum is σ = 24076800. Its totient is φ = 15422400.

The previous prime is 19668503. The next prime is 19668511. The reversal of 19668505 is 50586691.

It is not a de Polignac number, because 19668505 - 2¹ = 19668503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19668503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82176 + ... + 82414.

It is an arithmetic number, because the mean of its divisors is an integer number (1504800).

Almost surely, 2^19668505 is an apocalyptic number.

It is an amenable number.

19668505 is a deficient number, since it is larger than the sum of its proper divisors (4408295).

19668505 is a wasteful number, since it uses less digits than its factorization.

19668505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504.

The product of its (nonzero) digits is 64800, while the sum is 40.

The square root of 19668505 is about 4434.9188267656. The cubic root of 19668505 is about 269.9337057174.

The spelling of 19668505 in words is "nineteen million, six hundred sixty-eight thousand, five hundred five".