20129111 has 2 divisors, whose sum is σ = 20129112. Its totient is φ = 20129110.

The previous prime is 20129059. The next prime is 20129129. The reversal of 20129111 is 11192102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20129111 - 2⁶ = 20129047 is a prime.

It is a super-2 number, since 2×20129111² = 810362219300642, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20129111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20129141) 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, 10064555 + 10064556.

It is an arithmetic number, because the mean of its divisors is an integer number (10064556).

Almost surely, 2^20129111 is an apocalyptic number.

20129111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20129111 is an equidigital number, since it uses as much as digits as its factorization.

20129111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 20129111 is about 4486.5477819812. The cubic root of 20129111 is about 272.0246112030.

The spelling of 20129111 in words is "twenty million, one hundred twenty-nine thousand, one hundred eleven".