129727440 has 320 divisors, whose sum is σ = 491040000. Its totient is φ = 31352832.

The previous prime is 129727427. The next prime is 129727447. The reversal of 129727440 is 44727921.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 129727395 and 129727404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129727447) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1190106 + ... + 1190214.

It is an arithmetic number, because the mean of its divisors is an integer number (1534500).

Almost surely, 2^129727440 is an apocalyptic number.

129727440 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 129727440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245520000).

129727440 is an abundant number, since it is smaller than the sum of its proper divisors (361312560).

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

129727440 is a wasteful number, since it uses less digits than its factorization.

129727440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 129727440 is about 11389.7954327547. The cubic root of 129727440 is about 506.2254199314.

The spelling of 129727440 in words is "one hundred twenty-nine million, seven hundred twenty-seven thousand, four hundred forty".