129061840 has 40 divisors (see below), whose sum is σ = 303058728. Its totient is φ = 51110400.

The previous prime is 129061819. The next prime is 129061843. The reversal of 129061840 is 48160921.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 59105344 + 69956496 = 7688^2 + 8364^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×129061840³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129061843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94 + ... + 16066.

Almost surely, 2^129061840 is an apocalyptic number.

129061840 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 129061840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151529364).

129061840 is an abundant number, since it is smaller than the sum of its proper divisors (173996888).

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

129061840 is a wasteful number, since it uses less digits than its factorization.

129061840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16087 (or 16081 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 129061840 is about 11360.5387196207. The cubic root of 129061840 is about 505.3581617620.

The spelling of 129061840 in words is "one hundred twenty-nine million, sixty-one thousand, eight hundred forty".