129856540 has 48 divisors (see below), whose sum is σ = 314997984. Its totient is φ = 44441600.

The previous prime is 129856499. The next prime is 129856541. The reversal of 129856540 is 45658921.

It is a junction number, because it is equal to n+sod(n) for n = 129856493 and 129856502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129856541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13621 + ... + 21100.

It is an arithmetic number, because the mean of its divisors is an integer number (6562458).

Almost surely, 2^129856540 is an apocalyptic number.

129856540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129856540 is an abundant number, since it is smaller than the sum of its proper divisors (185141444).

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

129856540 is a wasteful number, since it uses less digits than its factorization.

129856540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34758 (or 34756 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 129856540 is about 11395.4613772326. The cubic root of 129856540 is about 506.3932899274.

The spelling of 129856540 in words is "one hundred twenty-nine million, eight hundred fifty-six thousand, five hundred forty".