129023999999 has 4 divisors (see below), whose sum is σ = 129736839960. Its totient is φ = 128311160040.

The previous prime is 129023999953. The next prime is 129024000019. The reversal of 129023999999 is 999999320921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999999320921 = 463907 ⋅2155603.

It is a cyclic number.

It is not a de Polignac number, because 129023999999 - 2²⁰ = 129022951423 is a prime.

It is a Duffinian number.

129023999999 is a modest number, since divided by 999999 gives 129023 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129023993999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356419709 + ... + 356420070.

It is an arithmetic number, because the mean of its divisors is an integer number (32434209990).

Almost surely, 2^129023999999 is an apocalyptic number.

129023999999 is a deficient number, since it is larger than the sum of its proper divisors (712839961).

129023999999 is an equidigital number, since it uses as much as digits as its factorization.

129023999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712839960.

The product of its (nonzero) digits is 57395628, while the sum is 71.

The spelling of 129023999999 in words is "one hundred twenty-nine billion, twenty-three million, nine hundred ninety-nine thousand, nine hundred ninety-nine".