20881369 has 2 divisors, whose sum is σ = 20881370. Its totient is φ = 20881368.

The previous prime is 20881349. The next prime is 20881381. The reversal of 20881369 is 96318802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17598025 + 3283344 = 4195^2 + 1812^2 .

It is a cyclic number.

It is not a de Polignac number, because 20881369 - 2⁷ = 20881241 is a prime.

It is a super-2 number, since 2×20881369² = 872063142628322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20881319) 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, 10440684 + 10440685.

It is an arithmetic number, because the mean of its divisors is an integer number (10440685).

Almost surely, 2^20881369 is an apocalyptic number.

It is an amenable number.

20881369 is a deficient number, since it is larger than the sum of its proper divisors (1).

20881369 is an equidigital number, since it uses as much as digits as its factorization.

20881369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 20881369 is about 4569.6136598185. The cubic root of 20881369 is about 275.3719221137.

The spelling of 20881369 in words is "twenty million, eight hundred eighty-one thousand, three hundred sixty-nine".