16684921 has 8 divisors (see below), whose sum is σ = 18255744. Its totient is φ = 15123120.

The previous prime is 16684901. The next prime is 16684931. The reversal of 16684921 is 12948661.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 16684921 - 2¹¹ = 16682873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16684901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1971 + ... + 6103.

It is an arithmetic number, because the mean of its divisors is an integer number (2281968).

Almost surely, 2^16684921 is an apocalyptic number.

16684921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16684921 is a deficient number, since it is larger than the sum of its proper divisors (1570823).

16684921 is a wasteful number, since it uses less digits than its factorization.

16684921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4511.

The product of its digits is 20736, while the sum is 37.

The square root of 16684921 is about 4084.7179829212. The cubic root of 16684921 is about 255.5296998906.

The spelling of 16684921 in words is "sixteen million, six hundred eighty-four thousand, nine hundred twenty-one".