129200020 has 24 divisors (see below), whose sum is σ = 277939368. Its totient is φ = 50419200.

The previous prime is 129200011. The next prime is 129200047. The reversal of 129200020 is 20002921.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 104976 + 129095044 = 324^2 + 11362^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129199967 and 129200003.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 77961 + ... + 79600.

It is an arithmetic number, because the mean of its divisors is an integer number (11580807).

Almost surely, 2^129200020 is an apocalyptic number.

129200020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129200020 is an abundant number, since it is smaller than the sum of its proper divisors (148739348).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129200020 is a wasteful number, since it uses less digits than its factorization.

129200020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157611 (or 157609 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 129200020 is about 11366.6186704754. The cubic root of 129200020 is about 505.5384512633.

Adding to 129200020 its reverse (20002921), we get a palindrome (149202941).

The spelling of 129200020 in words is "one hundred twenty-nine million, two hundred thousand, twenty".