128517372 has 18 divisors (see below), whose sum is σ = 324863448. Its totient is φ = 42839112.

The previous prime is 128517359. The next prime is 128517373. The reversal of 128517372 is 273715821.

128517372 is a `hidden beast` number, since 1 + 285 + 1 + 7 + 372 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 3569927 = 128517372 / (1 + 2 + 8 + 5 + 1 + 7 + 3 + 7 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128517373) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1784928 + ... + 1784999.

Almost surely, 2^128517372 is an apocalyptic number.

128517372 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

128517372 is an abundant number, since it is smaller than the sum of its proper divisors (196346076).

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

128517372 is a wasteful number, since it uses less digits than its factorization.

128517372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3569937 (or 3569932 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 128517372 is about 11336.5502689310. The cubic root of 128517372 is about 504.6465153649.

The spelling of 128517372 in words is "one hundred twenty-eight million, five hundred seventeen thousand, three hundred seventy-two".