129691669 has 2 divisors, whose sum is σ = 129691670. Its totient is φ = 129691668.

The previous prime is 129691633. The next prime is 129691721. The reversal of 129691669 is 966196921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67076100 + 62615569 = 8190^2 + 7913^2 .

It is a cyclic number.

It is not a de Polignac number, because 129691669 - 2⁹ = 129691157 is a prime.

It is a super-2 number, since 2×129691669² = 33639858016011122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129697669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64845834 + 64845835.

It is an arithmetic number, because the mean of its divisors is an integer number (64845835).

Almost surely, 2^129691669 is an apocalyptic number.

It is an amenable number.

129691669 is a deficient number, since it is larger than the sum of its proper divisors (1).

129691669 is an equidigital number, since it uses as much as digits as its factorization.

129691669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 49.

The square root of 129691669 is about 11388.2250153393. The cubic root of 129691669 is about 506.1788868460.

The spelling of 129691669 in words is "one hundred twenty-nine million, six hundred ninety-one thousand, six hundred sixty-nine".