16966621 has 4 divisors (see below), whose sum is σ = 19390432. Its totient is φ = 14542812.

The previous prime is 16966603. The next prime is 16966627. The reversal of 16966621 is 12666961.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12666961 = 113 ⋅112097.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16966621 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 (16966627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1211895 + ... + 1211908.

It is an arithmetic number, because the mean of its divisors is an integer number (4847608).

Almost surely, 2^16966621 is an apocalyptic number.

It is an amenable number.

16966621 is a deficient number, since it is larger than the sum of its proper divisors (2423811).

16966621 is an equidigital number, since it uses as much as digits as its factorization.

16966621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2423810.

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

The square root of 16966621 is about 4119.0558384173. The cubic root of 16966621 is about 256.9597609435.

The spelling of 16966621 in words is "sixteen million, nine hundred sixty-six thousand, six hundred twenty-one".