16665225 has 24 divisors (see below), whose sum is σ = 28754112. Its totient is φ = 8500800.

The previous prime is 16665221. The next prime is 16665241. The reversal of 16665225 is 52256661.

It is a happy number.

It is not a de Polignac number, because 16665225 - 2² = 16665221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16665221) 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 23 ways as a sum of consecutive naturals, for example, 3106 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (1198088).

Almost surely, 2^16665225 is an apocalyptic number.

16665225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16665225 is a deficient number, since it is larger than the sum of its proper divisors (12088887).

16665225 is a wasteful number, since it uses less digits than its factorization.

16665225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9697 (or 9692 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 16665225 is about 4082.3063334346. The cubic root of 16665225 is about 255.4291121670.

The spelling of 16665225 in words is "sixteen million, six hundred sixty-five thousand, two hundred twenty-five".