129177721819 has 2 divisors, whose sum is σ = 129177721820. Its totient is φ = 129177721818.

The previous prime is 129177721741. The next prime is 129177721837. The reversal of 129177721819 is 918127771921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129177721819 - 2⁷ = 129177721691 is a prime.

It is a super-2 number, since 2×129177721819² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 129177721819.

It is not a weakly prime, because it can be changed into another prime (129177721879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64588860909 + 64588860910.

It is an arithmetic number, because the mean of its divisors is an integer number (64588860910).

Almost surely, 2^129177721819 is an apocalyptic number.

129177721819 is a deficient number, since it is larger than the sum of its proper divisors (1).

129177721819 is an equidigital number, since it uses as much as digits as its factorization.

129177721819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 55.

The spelling of 129177721819 in words is "one hundred twenty-nine billion, one hundred seventy-seven million, seven hundred twenty-one thousand, eight hundred nineteen".