19947666 has 8 divisors (see below), whose sum is σ = 39895344. Its totient is φ = 6649220.

The previous prime is 19947643. The next prime is 19947703. The reversal of 19947666 is 66674991.

It is a sphenic number, since it is the product of 3 distinct primes.

19947666 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1662300 + ... + 1662311.

It is an arithmetic number, because the mean of its divisors is an integer number (4986918).

Almost surely, 2^19947666 is an apocalyptic number.

19947666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

19947666 is a wasteful number, since it uses less digits than its factorization.

19947666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3324616.

The product of its digits is 489888, while the sum is 48.

The square root of 19947666 is about 4466.2810032509. The cubic root of 19947666 is about 271.2047942957.

The spelling of 19947666 in words is "nineteen million, nine hundred forty-seven thousand, six hundred sixty-six".