129998789 has 4 divisors (see below), whose sum is σ = 130142400. Its totient is φ = 129855180.

The previous prime is 129998753. The next prime is 129998809. The reversal of 129998789 is 987899921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 129998789 - 2¹² = 129994693 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129998189) 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, 70439 + ... + 72260.

It is an arithmetic number, because the mean of its divisors is an integer number (32535600).

Almost surely, 2^129998789 is an apocalyptic number.

It is an amenable number.

129998789 is a deficient number, since it is larger than the sum of its proper divisors (143611).

129998789 is an equidigital number, since it uses as much as digits as its factorization.

129998789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143610.

The product of its digits is 5878656, while the sum is 62.

The square root of 129998789 is about 11401.7011450046. The cubic root of 129998789 is about 506.5781289103.

The spelling of 129998789 in words is "one hundred twenty-nine million, nine hundred ninety-eight thousand, seven hundred eighty-nine".