129640019 has 2 divisors, whose sum is σ = 129640020. Its totient is φ = 129640018.

The previous prime is 129640013. The next prime is 129640087. The reversal of 129640019 is 910046921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129640019 - 2¹² = 129635923 is a prime.

It is a super-2 number, since 2×129640019² = 33613069052640722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129640013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64820009 + 64820010.

It is an arithmetic number, because the mean of its divisors is an integer number (64820010).

Almost surely, 2^129640019 is an apocalyptic number.

129640019 is a deficient number, since it is larger than the sum of its proper divisors (1).

129640019 is an equidigital number, since it uses as much as digits as its factorization.

129640019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 129640019 is about 11385.9570963534. The cubic root of 129640019 is about 506.1116822956. Note that the first 3 decimals are identical.

The spelling of 129640019 in words is "one hundred twenty-nine million, six hundred forty thousand, nineteen".