20666205 has 64 divisors (see below), whose sum is σ = 44236800. Its totient is φ = 8942400.

The previous prime is 20666201. The next prime is 20666209. The reversal of 20666205 is 50266602.

It is an interprime number because it is at equal distance from previous prime (20666201) and next prime (20666209).

It is not a de Polignac number, because 20666205 - 2² = 20666201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666201) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17380 + ... + 18530.

It is an arithmetic number, because the mean of its divisors is an integer number (691200).

Almost surely, 2^20666205 is an apocalyptic number.

It is an amenable number.

20666205 is an abundant number, since it is smaller than the sum of its proper divisors (23570595).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20666205 is a wasteful number, since it uses less digits than its factorization.

20666205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191 (or 1185 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20666205 is about 4546.0097888148. The cubic root of 20666205 is about 274.4228335752.

The spelling of 20666205 in words is "twenty million, six hundred sixty-six thousand, two hundred five".