20660197 has 2 divisors, whose sum is σ = 20660198. Its totient is φ = 20660196.

The previous prime is 20660183. The next prime is 20660203. The reversal of 20660197 is 79106602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20557156 + 103041 = 4534^2 + 321^2 .

It is a cyclic number.

It is not a de Polignac number, because 20660197 - 2¹⁵ = 20627429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20660137) 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 as a sum of consecutive naturals, namely, 10330098 + 10330099.

It is an arithmetic number, because the mean of its divisors is an integer number (10330099).

Almost surely, 2^20660197 is an apocalyptic number.

It is an amenable number.

20660197 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660197 is an equidigital number, since it uses as much as digits as its factorization.

20660197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 20660197 is about 4545.3489415005. The cubic root of 20660197 is about 274.3962379459.

Adding to 20660197 its reverse (79106602), we get a palindrome (99766799).

The spelling of 20660197 in words is "twenty million, six hundred sixty thousand, one hundred ninety-seven".