20666061 has 24 divisors (see below), whose sum is σ = 32364696. Its totient is φ = 12631680.

The previous prime is 20666047. The next prime is 20666077. The reversal of 20666061 is 16066602.

It can be written as a sum of positive squares in 4 ways, for example, as 4384836 + 16281225 = 2094^2 + 4035^2 .

It is not a de Polignac number, because 20666061 - 2⁹ = 20665549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19731 + ... + 20751.

It is an arithmetic number, because the mean of its divisors is an integer number (1348529).

Almost surely, 2^20666061 is an apocalyptic number.

It is an amenable number.

20666061 is a deficient number, since it is larger than the sum of its proper divisors (11698635).

20666061 is a wasteful number, since it uses less digits than its factorization.

20666061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1213 (or 1210 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 20666061 is about 4545.9939507219. The cubic root of 20666061 is about 274.4221961903.

The spelling of 20666061 in words is "twenty million, six hundred sixty-six thousand, sixty-one".