20266681 has 2 divisors, whose sum is σ = 20266682. Its totient is φ = 20266680.

The previous prime is 20266661. The next prime is 20266693. The reversal of 20266681 is 18666202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19501056 + 765625 = 4416^2 + 875^2 .

It is a cyclic number.

It is not a de Polignac number, because 20266681 - 2⁷ = 20266553 is a prime.

It is a super-2 number, since 2×20266681² = 821476717511522, which contains 22 as substring.

It is a Chen prime.

It is a magnanimous number.

It is not a weakly prime, because it can be changed into another prime (20266661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10133340 + 10133341.

It is an arithmetic number, because the mean of its divisors is an integer number (10133341).

Almost surely, 2^20266681 is an apocalyptic number.

It is an amenable number.

20266681 is a deficient number, since it is larger than the sum of its proper divisors (1).

20266681 is an equidigital number, since it uses as much as digits as its factorization.

20266681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 20266681 is about 4501.8530629064. The cubic root of 20266681 is about 272.6429113184.

The spelling of 20266681 in words is "twenty million, two hundred sixty-six thousand, six hundred eighty-one".