20668117 has 2 divisors, whose sum is σ = 20668118. Its totient is φ = 20668116.

The previous prime is 20668111. The next prime is 20668121. The reversal of 20668117 is 71186602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17230801 + 3437316 = 4151^2 + 1854^2 .

It is a cyclic number.

It is not a de Polignac number, because 20668117 - 2¹⁹ = 20143829 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20668111) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334058 + 10334059.

It is an arithmetic number, because the mean of its divisors is an integer number (10334059).

Almost surely, 2^20668117 is an apocalyptic number.

It is an amenable number.

20668117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20668117 is an equidigital number, since it uses as much as digits as its factorization.

20668117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20668117 is about 4546.2200782628. The cubic root of 20668117 is about 274.4312963494.

The spelling of 20668117 in words is "twenty million, six hundred sixty-eight thousand, one hundred seventeen".