20166647 has 4 divisors (see below), whose sum is σ = 20817216. Its totient is φ = 19516080.

The previous prime is 20166637. The next prime is 20166649. The reversal of 20166647 is 74666102.

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

It is a cyclic number.

It is not a de Polignac number, because 20166647 - 2⁴ = 20166631 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 (20166649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 325238 + ... + 325299.

It is an arithmetic number, because the mean of its divisors is an integer number (5204304).

Almost surely, 2^20166647 is an apocalyptic number.

20166647 is a deficient number, since it is larger than the sum of its proper divisors (650569).

20166647 is an equidigital number, since it uses as much as digits as its factorization.

20166647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650568.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20166647 is about 4490.7290054066. The cubic root of 20166647 is about 272.1935932563.

The spelling of 20166647 in words is "twenty million, one hundred sixty-six thousand, six hundred forty-seven".