129831917 has 2 divisors, whose sum is σ = 129831918. Its totient is φ = 129831916.

The previous prime is 129831913. The next prime is 129831929. The reversal of 129831917 is 719138921.

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., 98684356 + 31147561 = 9934^2 + 5581^2 .

It is an emirp because it is prime and its reverse (719138921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129831917 - 2² = 129831913 is a prime.

It is equal to p_7369295 and since 129831917 and 7369295 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129831913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64915958 + 64915959.

It is an arithmetic number, because the mean of its divisors is an integer number (64915959).

Almost surely, 2^129831917 is an apocalyptic number.

It is an amenable number.

129831917 is a deficient number, since it is larger than the sum of its proper divisors (1).

129831917 is an equidigital number, since it uses as much as digits as its factorization.

129831917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 41.

The square root of 129831917 is about 11394.3809397439. The cubic root of 129831917 is about 506.3612809885.

The spelling of 129831917 in words is "one hundred twenty-nine million, eight hundred thirty-one thousand, nine hundred seventeen".