129712257928 has 32 divisors (see below), whose sum is σ = 271791767520. Its totient is φ = 57522064000.

The previous prime is 129712257893. The next prime is 129712257943. The reversal of 129712257928 is 829752217921.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17972038 + ... + 17979253.

It is an arithmetic number, because the mean of its divisors is an integer number (8493492735).

Almost surely, 2^129712257928 is an apocalyptic number.

It is an amenable number.

129712257928 is an abundant number, since it is smaller than the sum of its proper divisors (142079509592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129712257928 is a wasteful number, since it uses less digits than its factorization.

129712257928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35951349 (or 35951345 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 55.

It can be divided in two parts, 129712 and 257928, that added together give a triangular number (387640 = T₈₈₀).

The spelling of 129712257928 in words is "one hundred twenty-nine billion, seven hundred twelve million, two hundred fifty-seven thousand, nine hundred twenty-eight".