129291997 has 2 divisors, whose sum is σ = 129291998. Its totient is φ = 129291996.

The previous prime is 129291961. The next prime is 129292003. The reversal of 129291997 is 799192921.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121418361 + 7873636 = 11019^2 + 2806^2 .

It is a cyclic number.

It is not a de Polignac number, because 129291997 - 2²³ = 120903389 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129291997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129292997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64645998 + 64645999.

It is an arithmetic number, because the mean of its divisors is an integer number (64645999).

Almost surely, 2^129291997 is an apocalyptic number.

It is an amenable number.

129291997 is a deficient number, since it is larger than the sum of its proper divisors (1).

129291997 is an equidigital number, since it uses as much as digits as its factorization.

129291997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 183708, while the sum is 49.

The square root of 129291997 is about 11370.6638768367. The cubic root of 129291997 is about 505.6583864372.

The spelling of 129291997 in words is "one hundred twenty-nine million, two hundred ninety-one thousand, nine hundred ninety-seven".