20668841 has 2 divisors, whose sum is σ = 20668842. Its totient is φ = 20668840.

The previous prime is 20668831. The next prime is 20668859. The reversal of 20668841 is 14886602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19545241 + 1123600 = 4421^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 20668841 - 2⁶ = 20668777 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20668811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334420 + 10334421.

It is an arithmetic number, because the mean of its divisors is an integer number (10334421).

Almost surely, 2^20668841 is an apocalyptic number.

It is an amenable number.

20668841 is a deficient number, since it is larger than the sum of its proper divisors (1).

20668841 is an equidigital number, since it uses as much as digits as its factorization.

20668841 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 20668841 is about 4546.2997041550. The cubic root of 20668841 is about 274.4345007364.

The spelling of 20668841 in words is "twenty million, six hundred sixty-eight thousand, eight hundred forty-one".