19928666 has 8 divisors (see below), whose sum is σ = 30399840. Its totient is φ = 9795388.

The previous prime is 19928653. The next prime is 19928677. The reversal of 19928666 is 66682991.

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

It is a self number, because there is not a number n which added to its sum of digits gives 19928666.

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, 84326 + ... + 84561.

It is an arithmetic number, because the mean of its divisors is an integer number (3799980).

Almost surely, 2^19928666 is an apocalyptic number.

19928666 is a deficient number, since it is larger than the sum of its proper divisors (10471174).

19928666 is a wasteful number, since it uses less digits than its factorization.

19928666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168948.

The product of its digits is 279936, while the sum is 47.

The square root of 19928666 is about 4464.1534471835. The cubic root of 19928666 is about 271.1186601086.

The spelling of 19928666 in words is "nineteen million, nine hundred twenty-eight thousand, six hundred sixty-six".