129638347991 has 2 divisors, whose sum is σ = 129638347992. Its totient is φ = 129638347990.

The previous prime is 129638347963. The next prime is 129638347997. The reversal of 129638347991 is 199743836921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129638347991 - 2²² = 129634153687 is a prime.

It is a super-2 number, since 2×129638347991² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129638347997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64819173995 + 64819173996.

It is an arithmetic number, because the mean of its divisors is an integer number (64819173996).

Almost surely, 2^129638347991 is an apocalyptic number.

129638347991 is a deficient number, since it is larger than the sum of its proper divisors (1).

129638347991 is an equidigital number, since it uses as much as digits as its factorization.

129638347991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17635968, while the sum is 62.

The spelling of 129638347991 in words is "one hundred twenty-nine billion, six hundred thirty-eight million, three hundred forty-seven thousand, nine hundred ninety-one".