129728117 has 2 divisors, whose sum is σ = 129728118. Its totient is φ = 129728116.

The previous prime is 129728113. The next prime is 129728167. The reversal of 129728117 is 711827921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85119076 + 44609041 = 9226^2 + 6679^2 .

It is a cyclic number.

It is not a de Polignac number, because 129728117 - 2² = 129728113 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129728111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64864058 + 64864059.

It is an arithmetic number, because the mean of its divisors is an integer number (64864059).

Almost surely, 2^129728117 is an apocalyptic number.

It is an amenable number.

129728117 is a deficient number, since it is larger than the sum of its proper divisors (1).

129728117 is an equidigital number, since it uses as much as digits as its factorization.

129728117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 38.

The square root of 129728117 is about 11389.8251523015. The cubic root of 129728117 is about 506.2263005316.

The spelling of 129728117 in words is "one hundred twenty-nine million, seven hundred twenty-eight thousand, one hundred seventeen".