129720863999 has 4 divisors (see below), whose sum is σ = 129721593864. Its totient is φ = 129720134136.

The previous prime is 129720863981. The next prime is 129720864061. The reversal of 129720863999 is 999368027921.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 999368027921 = 19 ⋅52598317259.

It is a cyclic number.

It is not a de Polignac number, because 129720863999 - 2¹² = 129720859903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129720863939) 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, 94304 + ... + 518010.

It is an arithmetic number, because the mean of its divisors is an integer number (32430398466).

Almost surely, 2^129720863999 is an apocalyptic number.

129720863999 is a deficient number, since it is larger than the sum of its proper divisors (729865).

129720863999 is an equidigital number, since it uses as much as digits as its factorization.

129720863999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729864.

The product of its (nonzero) digits is 26453952, while the sum is 65.

The spelling of 129720863999 in words is "one hundred twenty-nine billion, seven hundred twenty million, eight hundred sixty-three thousand, nine hundred ninety-nine".