129728122 has 8 divisors (see below), whose sum is σ = 206038836. Its totient is φ = 61048512.

The previous prime is 129728117. The next prime is 129728167. The reversal of 129728122 is 221827921.

It can be written as a sum of positive squares in 2 ways, for example, as 123632161 + 6095961 = 11119^2 + 2469^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (34), and also a Moran number because the ratio is a prime number: 3815533 = 129728122 / (1 + 2 + 9 + 7 + 2 + 8 + 1 + 2 + 2).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1907733 + ... + 1907800.

Almost surely, 2^129728122 is an apocalyptic number.

129728122 is a deficient number, since it is larger than the sum of its proper divisors (76310714).

129728122 is a wasteful number, since it uses less digits than its factorization.

129728122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3815552.

The product of its digits is 8064, while the sum is 34.

The square root of 129728122 is about 11389.8253717957. The cubic root of 129728122 is about 506.2263070352.

The spelling of 129728122 in words is "one hundred twenty-nine million, seven hundred twenty-eight thousand, one hundred twenty-two".