129439969 has 2 divisors, whose sum is σ = 129439970. Its totient is φ = 129439968.

The previous prime is 129439931. The next prime is 129440039. The reversal of 129439969 is 969934921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98247744 + 31192225 = 9912^2 + 5585^2 .

It is a cyclic number.

It is not a de Polignac number, because 129439969 - 2¹⁷ = 129308897 is a prime.

It is a super-2 number, since 2×129439969² = 33509411149441922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129439069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64719984 + 64719985.

It is an arithmetic number, because the mean of its divisors is an integer number (64719985).

Almost surely, 2^129439969 is an apocalyptic number.

It is an amenable number.

129439969 is a deficient number, since it is larger than the sum of its proper divisors (1).

129439969 is an equidigital number, since it uses as much as digits as its factorization.

129439969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 944784, while the sum is 52.

The square root of 129439969 is about 11377.1687602848. The cubic root of 129439969 is about 505.8512180588.

The spelling of 129439969 in words is "one hundred twenty-nine million, four hundred thirty-nine thousand, nine hundred sixty-nine".