16666985 has 4 divisors (see below), whose sum is σ = 20000388. Its totient is φ = 13333584.

The previous prime is 16666961. The next prime is 16666997. The reversal of 16666985 is 58966661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7327849 + 9339136 = 2707^2 + 3056^2 .

It is a cyclic number.

It is not a de Polignac number, because 16666985 - 2⁶ = 16666921 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666694 + ... + 1666703.

It is an arithmetic number, because the mean of its divisors is an integer number (5000097).

Almost surely, 2^16666985 is an apocalyptic number.

It is an amenable number.

16666985 is a deficient number, since it is larger than the sum of its proper divisors (3333403).

16666985 is an equidigital number, since it uses as much as digits as its factorization.

16666985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3333402.

The product of its digits is 466560, while the sum is 47.

The square root of 16666985 is about 4082.5218921642. The cubic root of 16666985 is about 255.4381037331.

The spelling of 16666985 in words is "sixteen million, six hundred sixty-six thousand, nine hundred eighty-five".