128634864 has 80 divisors (see below), whose sum is σ = 357358080. Its totient is φ = 39744000.

The previous prime is 128634853. The next prime is 128634881. The reversal of 128634864 is 468436821.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (221184) is a multiple of the sum of its prime divisors (3072).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41364 + ... + 44364.

It is an arithmetic number, because the mean of its divisors is an integer number (4466976).

Almost surely, 2^128634864 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 128634864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178679040).

128634864 is an abundant number, since it is smaller than the sum of its proper divisors (228723216).

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

128634864 is a wasteful number, since it uses less digits than its factorization.

128634864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3078 (or 3072 counting only the distinct ones).

The product of its digits is 221184, while the sum is 42.

The square root of 128634864 is about 11341.7310848036. The cubic root of 128634864 is about 504.8002529964.

The spelling of 128634864 in words is "one hundred twenty-eight million, six hundred thirty-four thousand, eight hundred sixty-four".