128117664 has 72 divisors (see below), whose sum is σ = 365427972. Its totient is φ = 42577920.

The previous prime is 128117641. The next prime is 128117677. The reversal of 128117664 is 466711821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 127509264 + 608400 = 11292^2 + 780^2 .

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 an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190032 + ... + 190704.

Almost surely, 2^128117664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128117664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182713986).

128117664 is an abundant number, since it is smaller than the sum of its proper divisors (237310308).

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

128117664 is a wasteful number, since it uses less digits than its factorization.

128117664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 1339 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 128117664 is about 11318.9073677630. The cubic root of 128117664 is about 504.1227969873.

The spelling of 128117664 in words is "one hundred twenty-eight million, one hundred seventeen thousand, six hundred sixty-four".