129111817 has 2 divisors, whose sum is σ = 129111818. Its totient is φ = 129111816.

The previous prime is 129111769. The next prime is 129111877. The reversal of 129111817 is 718111921.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102030201 + 27081616 = 10101^2 + 5204^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129111817 is a prime.

It is a super-2 number, since 2×129111817² = 33339722578082978, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129111877) 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, 64555908 + 64555909.

It is an arithmetic number, because the mean of its divisors is an integer number (64555909).

Almost surely, 2^129111817 is an apocalyptic number.

It is an amenable number.

129111817 is a deficient number, since it is larger than the sum of its proper divisors (1).

129111817 is an equidigital number, since it uses as much as digits as its factorization.

129111817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 31.

The square root of 129111817 is about 11362.7380943151. The cubic root of 129111817 is about 505.4233837918.

The spelling of 129111817 in words is "one hundred twenty-nine million, one hundred eleven thousand, eight hundred seventeen".