129809540 has 48 divisors (see below), whose sum is σ = 312195072. Its totient is φ = 44413056.

The previous prime is 129809489. The next prime is 129809557. The reversal of 129809540 is 45908921.

It is a junction number, because it is equal to n+sod(n) for n = 129809494 and 129809503.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118877 + ... + 119963.

It is an arithmetic number, because the mean of its divisors is an integer number (6504064).

Almost surely, 2^129809540 is an apocalyptic number.

129809540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129809540 is an abundant number, since it is smaller than the sum of its proper divisors (182385532).

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

129809540 is a wasteful number, since it uses less digits than its factorization.

129809540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1956 (or 1954 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 129809540 is about 11393.3989660680. The cubic root of 129809540 is about 506.3321882515.

The spelling of 129809540 in words is "one hundred twenty-nine million, eight hundred nine thousand, five hundred forty".