16666225 has 6 divisors (see below), whose sum is σ = 20666150. Its totient is φ = 13332960.

The previous prime is 16666219. The next prime is 16666231. The reversal of 16666225 is 52266661.

It is an interprime number because it is at equal distance from previous prime (16666219) and next prime (16666231).

It can be written as a sum of positive squares in 3 ways, for example, as 11664 + 16654561 = 108^2 + 4081^2 .

It is not a de Polignac number, because 16666225 - 2³ = 16666217 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 333300 + ... + 333349.

Almost surely, 2^16666225 is an apocalyptic number.

It is an amenable number.

16666225 is a deficient number, since it is larger than the sum of its proper divisors (3999925).

16666225 is an equidigital number, since it uses as much as digits as its factorization.

16666225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666659 (or 666654 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 16666225 is about 4082.4288113818. The cubic root of 16666225 is about 255.4342210890.

The spelling of 16666225 in words is "sixteen million, six hundred sixty-six thousand, two hundred twenty-five".