20766397 has 2 divisors, whose sum is σ = 20766398. Its totient is φ = 20766396.

The previous prime is 20766391. The next prime is 20766419. The reversal of 20766397 is 79366702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19263321 + 1503076 = 4389^2 + 1226^2 .

It is a cyclic number.

It is not a de Polignac number, because 20766397 - 2⁷ = 20766269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20766391) 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, 10383198 + 10383199.

It is an arithmetic number, because the mean of its divisors is an integer number (10383199).

Almost surely, 2^20766397 is an apocalyptic number.

It is an amenable number.

20766397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20766397 is an equidigital number, since it uses as much as digits as its factorization.

20766397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 95256, while the sum is 40.

The square root of 20766397 is about 4557.0162387246. The cubic root of 20766397 is about 274.8655960299.

The spelling of 20766397 in words is "twenty million, seven hundred sixty-six thousand, three hundred ninety-seven".