16643225 has 12 divisors (see below), whose sum is σ = 20695104. Its totient is φ = 13277520.

The previous prime is 16643213. The next prime is 16643227. The reversal of 16643225 is 52234661.

It is a de Polignac number, because none of the positive numbers 2^k-16643225 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 (16643227) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11492 + ... + 12858.

It is an arithmetic number, because the mean of its divisors is an integer number (1724592).

Almost surely, 2^16643225 is an apocalyptic number.

It is an amenable number.

16643225 is a deficient number, since it is larger than the sum of its proper divisors (4051879).

16643225 is a wasteful number, since it uses less digits than its factorization.

16643225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1864 (or 1859 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 16643225 is about 4079.6108883079. The cubic root of 16643225 is about 255.3166641393.

Adding to 16643225 its reverse (52234661), we get a palindrome (68877886).

The spelling of 16643225 in words is "sixteen million, six hundred forty-three thousand, two hundred twenty-five".