20665101 has 16 divisors (see below), whose sum is σ = 28410624. Its totient is φ = 13353984.

The previous prime is 20665093. The next prime is 20665111. The reversal of 20665101 is 10156602.

It is a happy number.

It is not a de Polignac number, because 20665101 - 2³ = 20665093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20665111) 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 15 ways as a sum of consecutive naturals, for example, 15285 + ... + 16581.

It is an arithmetic number, because the mean of its divisors is an integer number (1775664).

Almost surely, 2^20665101 is an apocalyptic number.

It is an amenable number.

20665101 is a deficient number, since it is larger than the sum of its proper divisors (7745523).

20665101 is a wasteful number, since it uses less digits than its factorization.

20665101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20665101 is about 4545.8883620256. Note that the first 3 decimals coincide. The cubic root of 20665101 is about 274.4179468821.

The spelling of 20665101 in words is "twenty million, six hundred sixty-five thousand, one hundred one".