20666887 has 8 divisors (see below), whose sum is σ = 21424896. Its totient is φ = 19922232.

The previous prime is 20666869. The next prime is 20666929. The reversal of 20666887 is 78866602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20666887 - 2⁷ = 20666759 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 (20666827) 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 7 ways as a sum of consecutive naturals, for example, 133 + ... + 6430.

It is an arithmetic number, because the mean of its divisors is an integer number (2678112).

Almost surely, 2^20666887 is an apocalyptic number.

20666887 is a deficient number, since it is larger than the sum of its proper divisors (758009).

20666887 is an equidigital number, since it uses as much as digits as its factorization.

20666887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6677.

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 20666887 is about 4546.0847990331. The cubic root of 20666887 is about 274.4258522606.

The spelling of 20666887 in words is "twenty million, six hundred sixty-six thousand, eight hundred eighty-seven".