20668111 has 2 divisors, whose sum is σ = 20668112. Its totient is φ = 20668110.

The previous prime is 20668091. The next prime is 20668117. The reversal of 20668111 is 11186602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20668111 - 2¹⁵ = 20635343 is a prime.

It is a congruent number.

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 good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334055 + 10334056.

It is an arithmetic number, because the mean of its divisors is an integer number (10334056).

Almost surely, 2^20668111 is an apocalyptic number.

20668111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20668111 is an equidigital number, since it uses as much as digits as its factorization.

20668111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20668111 is about 4546.2194183739. The cubic root of 20668111 is about 274.4312697934.

The spelling of 20668111 in words is "twenty million, six hundred sixty-eight thousand, one hundred eleven".