129971771 has 2 divisors, whose sum is σ = 129971772. Its totient is φ = 129971770.

The previous prime is 129971767. The next prime is 129971791. The reversal of 129971771 is 177179921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129971771 - 2² = 129971767 is a prime.

It is a super-2 number, since 2×129971771² = 33785322513752882, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (129971731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64985885 + 64985886.

It is an arithmetic number, because the mean of its divisors is an integer number (64985886).

Almost surely, 2^129971771 is an apocalyptic number.

129971771 is a deficient number, since it is larger than the sum of its proper divisors (1).

129971771 is an equidigital number, since it uses as much as digits as its factorization.

129971771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55566, while the sum is 44.

The square root of 129971771 is about 11400.5162602401. The cubic root of 129971771 is about 506.5430319778.

The spelling of 129971771 in words is "one hundred twenty-nine million, nine hundred seventy-one thousand, seven hundred seventy-one".