129720678 has 16 divisors (see below), whose sum is σ = 267810816. Its totient is φ = 41845320.

The previous prime is 129720673. The next prime is 129720697. The reversal of 129720678 is 876027921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129720671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 348526 + ... + 348897.

It is an arithmetic number, because the mean of its divisors is an integer number (16738176).

Almost surely, 2^129720678 is an apocalyptic number.

129720678 is an abundant number, since it is smaller than the sum of its proper divisors (138090138).

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

129720678 is a wasteful number, since it uses less digits than its factorization.

129720678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697459.

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 129720678 is about 11389.4985842222. The cubic root of 129720678 is about 506.2166241676.

The spelling of 129720678 in words is "one hundred twenty-nine million, seven hundred twenty thousand, six hundred seventy-eight".