20666000217 has 4 divisors (see below), whose sum is σ = 27554666960. Its totient is φ = 13777333476.

The previous prime is 20666000209. The next prime is 20666000263. The reversal of 20666000217 is 71200066602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20666000217 - 2³ = 20666000209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20666000287) 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, 3444333367 + ... + 3444333372.

It is an arithmetic number, because the mean of its divisors is an integer number (6888666740).

Almost surely, 2^20666000217 is an apocalyptic number.

It is an amenable number.

20666000217 is a deficient number, since it is larger than the sum of its proper divisors (6888666743).

20666000217 is an equidigital number, since it uses as much as digits as its factorization.

20666000217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6888666742.

The product of its (nonzero) digits is 6048, while the sum is 30.

Adding to 20666000217 its reverse (71200066602), we get a palindrome (91866066819).

The spelling of 20666000217 in words is "twenty billion, six hundred sixty-six million, two hundred seventeen", and thus it is an aban number.