16916621 has 4 divisors (see below), whose sum is σ = 16972032. Its totient is φ = 16861212.

The previous prime is 16916611. The next prime is 16916671. The reversal of 16916621 is 12661961.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16916621 - 2¹⁴ = 16900237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16916611) by changing a digit.

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, 27245 + ... + 27858.

It is an arithmetic number, because the mean of its divisors is an integer number (4243008).

Almost surely, 2^16916621 is an apocalyptic number.

It is an amenable number.

16916621 is a deficient number, since it is larger than the sum of its proper divisors (55411).

16916621 is an equidigital number, since it uses as much as digits as its factorization.

16916621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55410.

The product of its digits is 3888, while the sum is 32.

The square root of 16916621 is about 4112.9820082271. The cubic root of 16916621 is about 256.7070956348.

The spelling of 16916621 in words is "sixteen million, nine hundred sixteen thousand, six hundred twenty-one".