129721306 has 16 divisors (see below), whose sum is σ = 228600288. Its totient is φ = 54428400.

The previous prime is 129721289. The next prime is 129721307. The reversal of 129721306 is 603127921.

It is not an unprimeable number, because it can be changed into a prime (129721307) 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, 226500 + ... + 227071.

It is an arithmetic number, because the mean of its divisors is an integer number (14287518).

Almost surely, 2^129721306 is an apocalyptic number.

129721306 is a deficient number, since it is larger than the sum of its proper divisors (98878982).

129721306 is a wasteful number, since it uses less digits than its factorization.

129721306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453597.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 129721306 is about 11389.5261534447. The cubic root of 129721306 is about 506.2174410600.

The spelling of 129721306 in words is "one hundred twenty-nine million, seven hundred twenty-one thousand, three hundred six".