129628387 has 4 divisors (see below), whose sum is σ = 148146736. Its totient is φ = 111110040.

The previous prime is 129628379. The next prime is 129628403. The reversal of 129628387 is 783826921.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 129628387 - 2³ = 129628379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129628327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9259164 + ... + 9259177.

It is an arithmetic number, because the mean of its divisors is an integer number (37036684).

Almost surely, 2^129628387 is an apocalyptic number.

129628387 is a deficient number, since it is larger than the sum of its proper divisors (18518349).

129628387 is an equidigital number, since it uses as much as digits as its factorization.

129628387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18518348.

The product of its digits is 290304, while the sum is 46.

The square root of 129628387 is about 11385.4462802299. The cubic root of 129628387 is about 506.0965448218.

The spelling of 129628387 in words is "one hundred twenty-nine million, six hundred twenty-eight thousand, three hundred eighty-seven".