19966668 has 48 divisors (see below), whose sum is σ = 49330176. Its totient is φ = 6272640.

The previous prime is 19966657. The next prime is 19966679. The reversal of 19966668 is 86666991.

It is an interprime number because it is at equal distance from previous prime (19966657) and next prime (19966679).

It is a self number, because there is not a number n which added to its sum of digits gives 19966668.

It is a congruent number.

It is an unprimeable number.

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, 19653 + ... + 20643.

It is an arithmetic number, because the mean of its divisors is an integer number (1027712).

Almost surely, 2^19966668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19966668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24665088).

19966668 is an abundant number, since it is smaller than the sum of its proper divisors (29363508).

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

19966668 is a wasteful number, since it uses less digits than its factorization.

19966668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1094 (or 1092 counting only the distinct ones).

The product of its digits is 839808, while the sum is 51.

The square root of 19966668 is about 4468.4077701123. The cubic root of 19966668 is about 271.2908828636.

The spelling of 19966668 in words is "nineteen million, nine hundred sixty-six thousand, six hundred sixty-eight".