129976728 has 64 divisors (see below), whose sum is σ = 372207360. Its totient is φ = 37051776.

The previous prime is 129976727. The next prime is 129976729. The reversal of 129976728 is 827679921.

It is an interprime number because it is at equal distance from previous prime (129976727) and next prime (129976729).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129976727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142851 + ... + 143757.

It is an arithmetic number, because the mean of its divisors is an integer number (5815740).

Almost surely, 2^129976728 is an apocalyptic number.

It is an amenable number.

129976728 is an abundant number, since it is smaller than the sum of its proper divisors (242230632).

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

129976728 is a wasteful number, since it uses less digits than its factorization.

129976728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1776 (or 1772 counting only the distinct ones).

The product of its digits is 762048, while the sum is 51.

The square root of 129976728 is about 11400.7336606027. The cubic root of 129976728 is about 506.5494715861.

The spelling of 129976728 in words is "one hundred twenty-nine million, nine hundred seventy-six thousand, seven hundred twenty-eight".