129597440 has 128 divisors (see below), whose sum is σ = 358607520. Its totient is φ = 44040192.

The previous prime is 129597427. The next prime is 129597449. The reversal of 129597440 is 44795921.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129597449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1146824 + ... + 1146936.

Almost surely, 2^129597440 is an apocalyptic number.

129597440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129597440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179303760).

129597440 is an abundant number, since it is smaller than the sum of its proper divisors (229010080).

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

129597440 is an frugal number, since it uses more digits than its factorization.

129597440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 129597440 is about 11384.0871395119. The cubic root of 129597440 is about 506.0562670794.

The spelling of 129597440 in words is "one hundred twenty-nine million, five hundred ninety-seven thousand, four hundred forty".