20668147 has 2 divisors, whose sum is σ = 20668148. Its totient is φ = 20668146.

The previous prime is 20668139. The next prime is 20668157. The reversal of 20668147 is 74186602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20668147 - 2³ = 20668139 is a prime.

It is not a weakly prime, because it can be changed into another prime (20668117) 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, 10334073 + 10334074.

It is an arithmetic number, because the mean of its divisors is an integer number (10334074).

Almost surely, 2^20668147 is an apocalyptic number.

20668147 is a deficient number, since it is larger than the sum of its proper divisors (1).

20668147 is an equidigital number, since it uses as much as digits as its factorization.

20668147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20668147 is about 4546.2233777059. The cubic root of 20668147 is about 274.4314291293.

The spelling of 20668147 in words is "twenty million, six hundred sixty-eight thousand, one hundred forty-seven".