129971993 has 2 divisors, whose sum is σ = 129971994. Its totient is φ = 129971992.

The previous prime is 129971981. The next prime is 129971999. The reversal of 129971993 is 399179921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89624089 + 40347904 = 9467^2 + 6352^2 .

It is a cyclic number.

It is not a de Polignac number, because 129971993 - 2²⁴ = 113194777 is a prime.

It is not a weakly prime, because it can be changed into another prime (129971999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64985996 + 64985997.

It is an arithmetic number, because the mean of its divisors is an integer number (64985997).

Almost surely, 2^129971993 is an apocalyptic number.

It is an amenable number.

129971993 is a deficient number, since it is larger than the sum of its proper divisors (1).

129971993 is an equidigital number, since it uses as much as digits as its factorization.

129971993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 275562, while the sum is 50.

The square root of 129971993 is about 11400.5259966372. The cubic root of 129971993 is about 506.5433203801.

The spelling of 129971993 in words is "one hundred twenty-nine million, nine hundred seventy-one thousand, nine hundred ninety-three".