129287840 has 48 divisors (see below), whose sum is σ = 333214560. Its totient is φ = 47013120.

The previous prime is 129287833. The next prime is 129287857. The reversal of 129287840 is 48782921.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 34970 + ... + 38489.

It is an arithmetic number, because the mean of its divisors is an integer number (6941970).

Almost surely, 2^129287840 is an apocalyptic number.

129287840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129287840 is an abundant number, since it is smaller than the sum of its proper divisors (203926720).

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

129287840 is a wasteful number, since it uses less digits than its factorization.

129287840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73485 (or 73477 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 129287840 is about 11370.4810804117. The cubic root of 129287840 is about 505.6529670648.

The spelling of 129287840 in words is "one hundred twenty-nine million, two hundred eighty-seven thousand, eight hundred forty".