20666223 has 6 divisors (see below), whose sum is σ = 29851224. Its totient is φ = 13777476.

The previous prime is 20666221. The next prime is 20666249. The reversal of 20666223 is 32266602.

It is a happy number.

It is not a de Polignac number, because 20666223 - 2¹ = 20666221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666221) 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 5 ways as a sum of consecutive naturals, for example, 1148115 + ... + 1148132.

It is an arithmetic number, because the mean of its divisors is an integer number (4975204).

Almost surely, 2^20666223 is an apocalyptic number.

20666223 is a deficient number, since it is larger than the sum of its proper divisors (9185001).

20666223 is a wasteful number, since it uses less digits than its factorization.

20666223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296253 (or 2296250 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 20666223 is about 4546.0117685725. The cubic root of 20666223 is about 274.4229132481.

The spelling of 20666223 in words is "twenty million, six hundred sixty-six thousand, two hundred twenty-three".