20666299 has 4 divisors (see below), whose sum is σ = 21378960. Its totient is φ = 19953640.

The previous prime is 20666293. The next prime is 20666311. The reversal of 20666299 is 99266602.

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 20666299 - 2⁵ = 20666267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20666293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356287 + ... + 356344.

It is an arithmetic number, because the mean of its divisors is an integer number (5344740).

Almost surely, 2^20666299 is an apocalyptic number.

20666299 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20666299 is a deficient number, since it is larger than the sum of its proper divisors (712661).

20666299 is an equidigital number, since it uses as much as digits as its factorization.

20666299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712660.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 20666299 is about 4546.0201275401. The cubic root of 20666299 is about 274.4232496443.

The spelling of 20666299 in words is "twenty million, six hundred sixty-six thousand, two hundred ninety-nine".