129257240 has 64 divisors (see below), whose sum is σ = 346844160. Its totient is φ = 42387840.

The previous prime is 129257221. The next prime is 129257279. The reversal of 129257240 is 42752921.

It is a junction number, because it is equal to n+sod(n) for n = 129257197 and 129257206.

It is a congruent number.

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, 3596 + ... + 16475.

It is an arithmetic number, because the mean of its divisors is an integer number (5419440).

Almost surely, 2^129257240 is an apocalyptic number.

129257240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129257240 is an abundant number, since it is smaller than the sum of its proper divisors (217586920).

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

129257240 is a wasteful number, since it uses less digits than its factorization.

129257240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20112 (or 20108 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 129257240 is about 11369.1354112791. The cubic root of 129257240 is about 505.6130710682.

The spelling of 129257240 in words is "one hundred twenty-nine million, two hundred fifty-seven thousand, two hundred forty".