129523540 has 24 divisors (see below), whose sum is σ = 277788672. Its totient is φ = 50706720.

The previous prime is 129523531. The next prime is 129523553. The reversal of 129523540 is 45325921.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67956 + ... + 69835.

It is an arithmetic number, because the mean of its divisors is an integer number (11574528).

Almost surely, 2^129523540 is an apocalyptic number.

129523540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129523540 is an abundant number, since it is smaller than the sum of its proper divisors (148265132).

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

129523540 is a wasteful number, since it uses less digits than its factorization.

129523540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137847 (or 137845 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 129523540 is about 11380.8409179638. The cubic root of 129523540 is about 505.9600597553.

The spelling of 129523540 in words is "one hundred twenty-nine million, five hundred twenty-three thousand, five hundred forty".