19643668 has 12 divisors (see below), whose sum is σ = 37501632. Its totient is φ = 8928920.

The previous prime is 19643651. The next prime is 19643681. The reversal of 19643668 is 86634691.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223180 + ... + 223267.

It is an arithmetic number, because the mean of its divisors is an integer number (3125136).

Almost surely, 2^19643668 is an apocalyptic number.

It is an amenable number.

19643668 is a deficient number, since it is larger than the sum of its proper divisors (17857964).

19643668 is a wasteful number, since it uses less digits than its factorization.

19643668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446462 (or 446460 counting only the distinct ones).

The product of its digits is 186624, while the sum is 43.

The square root of 19643668 is about 4432.1177782184. The cubic root of 19643668 is about 269.8200355381.

The spelling of 19643668 in words is "nineteen million, six hundred forty-three thousand, six hundred sixty-eight".