16621664 has 12 divisors (see below), whose sum is σ = 32723964. Its totient is φ = 8310816.

The previous prime is 16621643. The next prime is 16621681. The reversal of 16621664 is 46612661.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 519427 = 16621664 / (1 + 6 + 6 + 2 + 1 + 6 + 6 + 4).

It is a self number, because there is not a number n which added to its sum of digits gives 16621664.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259682 + ... + 259745.

It is an arithmetic number, because the mean of its divisors is an integer number (2726997).

Almost surely, 2^16621664 is an apocalyptic number.

It is an amenable number.

16621664 is a deficient number, since it is larger than the sum of its proper divisors (16102300).

16621664 is an equidigital number, since it uses as much as digits as its factorization.

16621664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519437 (or 519429 counting only the distinct ones).

The product of its digits is 10368, while the sum is 32.

The square root of 16621664 is about 4076.9675004837. The cubic root of 16621664 is about 255.2063637725.

The spelling of 16621664 in words is "sixteen million, six hundred twenty-one thousand, six hundred sixty-four".