129897040 has 120 divisors (see below), whose sum is σ = 378491400. Its totient is φ = 41094144.

The previous prime is 129897007. The next prime is 129897041. The reversal of 129897040 is 40798921.

It can be written as a sum of positive squares in 4 ways, for example, as 17875984 + 112021056 = 4228^2 + 10584^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 129896984 and 129897002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129897041) 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 23 ways as a sum of consecutive naturals, for example, 49686 + ... + 52234.

It is an arithmetic number, because the mean of its divisors is an integer number (3154095).

Almost surely, 2^129897040 is an apocalyptic number.

129897040 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 129897040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189245700).

129897040 is an abundant number, since it is smaller than the sum of its proper divisors (248594360).

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

129897040 is a wasteful number, since it uses less digits than its factorization.

129897040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2589 (or 2576 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 129897040 is about 11397.2382619650. The cubic root of 129897040 is about 506.4459295467.

129897040 divided by its sum of digits (40) gives a triangular number (3247426 = T₂₅₄₈).

The spelling of 129897040 in words is "one hundred twenty-nine million, eight hundred ninety-seven thousand, forty".