128717280 has 72 divisors (see below), whose sum is σ = 439252632. Its totient is φ = 34324224.

The previous prime is 128717279. The next prime is 128717293. The reversal of 128717280 is 82717821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43254 + ... + 46133.

It is an arithmetic number, because the mean of its divisors is an integer number (6100731).

Almost surely, 2^128717280 is an apocalyptic number.

128717280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128717280 is an abundant number, since it is smaller than the sum of its proper divisors (310535352).

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

128717280 is a wasteful number, since it uses less digits than its factorization.

128717280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89408 (or 89397 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 128717280 is about 11345.3638108260. The cubic root of 128717280 is about 504.9080380203.

The spelling of 128717280 in words is "one hundred twenty-eight million, seven hundred seventeen thousand, two hundred eighty".