16644025 has 6 divisors (see below), whose sum is σ = 20638622. Its totient is φ = 13315200.

The previous prime is 16644013. The next prime is 16644029. The reversal of 16644025 is 52044661.

It can be written as a sum of positive squares in 3 ways, for example, as 795664 + 15848361 = 892^2 + 3981^2 .

It is not a de Polignac number, because 16644025 - 2⁷ = 16643897 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16643984 and 16644002.

It is not an unprimeable number, because it can be changed into a prime (16644029) 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 5 ways as a sum of consecutive naturals, for example, 332856 + ... + 332905.

Almost surely, 2^16644025 is an apocalyptic number.

It is an amenable number.

16644025 is a deficient number, since it is larger than the sum of its proper divisors (3994597).

16644025 is an equidigital number, since it uses as much as digits as its factorization.

16644025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665771 (or 665766 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 16644025 is about 4079.7089356963. The cubic root of 16644025 is about 255.3207548941.

Adding to 16644025 its reverse (52044661), we get a palindrome (68688686).

The spelling of 16644025 in words is "sixteen million, six hundred forty-four thousand, twenty-five".