19666668 has 48 divisors (see below), whose sum is σ = 52706304. Its totient is φ = 5591040.

The previous prime is 19666663. The next prime is 19666681. The reversal of 19666668 is 86666691.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (19666663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21133 + ... + 22043.

It is an arithmetic number, because the mean of its divisors is an integer number (1098048).

Almost surely, 2^19666668 is an apocalyptic number.

It is an amenable number.

19666668 is an abundant number, since it is smaller than the sum of its proper divisors (33039636).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19666668 is a wasteful number, since it uses less digits than its factorization.

19666668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1182 (or 1180 counting only the distinct ones).

The product of its digits is 559872, while the sum is 48.

The square root of 19666668 is about 4434.7117155459. The cubic root of 19666668 is about 269.9253016952.

It can be divided in two parts, 1 and 9666668, that added together give a palindrome (9666669).

The spelling of 19666668 in words is "nineteen million, six hundred sixty-six thousand, six hundred sixty-eight".