16645021 has 8 divisors (see below), whose sum is σ = 17249760. Its totient is φ = 16051152.

The previous prime is 16644977. The next prime is 16645033. The reversal of 16645021 is 12054661.

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 16645021 - 2¹¹ = 16642973 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 (16645051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 466 + ... + 5788.

It is an arithmetic number, because the mean of its divisors is an integer number (2156220).

Almost surely, 2^16645021 is an apocalyptic number.

It is an amenable number.

16645021 is a deficient number, since it is larger than the sum of its proper divisors (604739).

16645021 is an equidigital number, since it uses as much as digits as its factorization.

16645021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5435.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 16645021 is about 4079.8310014019. The cubic root of 16645021 is about 255.3258477007.

Adding to 16645021 its reverse (12054661), we get a palindrome (28699682).

The spelling of 16645021 in words is "sixteen million, six hundred forty-five thousand, twenty-one".