16921666 has 8 divisors (see below), whose sum is σ = 26718480. Its totient is φ = 8015508.

The previous prime is 16921657. The next prime is 16921673. The reversal of 16921666 is 66612961.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222616 + ... + 222691.

It is an arithmetic number, because the mean of its divisors is an integer number (3339810).

Almost surely, 2^16921666 is an apocalyptic number.

16921666 is a deficient number, since it is larger than the sum of its proper divisors (9796814).

16921666 is a wasteful number, since it uses less digits than its factorization.

16921666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445328.

The product of its digits is 23328, while the sum is 37.

The square root of 16921666 is about 4113.5952644858. The cubic root of 16921666 is about 256.7326121288.

The spelling of 16921666 in words is "sixteen million, nine hundred twenty-one thousand, six hundred sixty-six".