129721316 has 36 divisors (see below), whose sum is σ = 237174588. Its totient is φ = 62058048.

The previous prime is 129721307. The next prime is 129721351. The reversal of 129721316 is 613127921.

It can be written as a sum of positive squares in 2 ways, for example, as 56550400 + 73170916 = 7520^2 + 8554^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 468170 + ... + 468446.

It is an arithmetic number, because the mean of its divisors is an integer number (6588183).

Almost surely, 2^129721316 is an apocalyptic number.

It is an amenable number.

129721316 is a deficient number, since it is larger than the sum of its proper divisors (107453272).

129721316 is a wasteful number, since it uses less digits than its factorization.

129721316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428 (or 379 counting only the distinct ones).

The product of its digits is 4536, while the sum is 32.

The square root of 129721316 is about 11389.5265924445. The cubic root of 129721316 is about 506.2174540679.

The spelling of 129721316 in words is "one hundred twenty-nine million, seven hundred twenty-one thousand, three hundred sixteen".