129565020 has 96 divisors (see below), whose sum is σ = 399877632. Its totient is φ = 31143168.

The previous prime is 129565013. The next prime is 129565021. The reversal of 129565020 is 20565921.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129565021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31609 + ... + 35471.

It is an arithmetic number, because the mean of its divisors is an integer number (4165392).

Almost surely, 2^129565020 is an apocalyptic number.

129565020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129565020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199938816).

129565020 is an abundant number, since it is smaller than the sum of its proper divisors (270312612).

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

129565020 is a wasteful number, since it uses less digits than its factorization.

129565020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3931 (or 3929 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 129565020 is about 11382.6631330282. The cubic root of 129565020 is about 506.0140653394.

The spelling of 129565020 in words is "one hundred twenty-nine million, five hundred sixty-five thousand, twenty".