128213928 has 80 divisors (see below), whose sum is σ = 361047060. Its totient is φ = 42508800.

The previous prime is 128213879. The next prime is 128213963. The reversal of 128213928 is 829312821.

It can be written as a sum of positive squares in 2 ways, for example, as 128187684 + 26244 = 11322^2 + 162^2 .

It is a super-2 number, since 2×128213928² = 32877622666378368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

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

It is a junction number, because it is equal to n+sod(n) for n = 128213892 and 128213901.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 155758 + ... + 156578.

Almost surely, 2^128213928 is an apocalyptic number.

128213928 is a gapful number since it is divisible by the number (18) 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 128213928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180523530).

128213928 is an abundant number, since it is smaller than the sum of its proper divisors (232833132).

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

128213928 is a wasteful number, since it uses less digits than its factorization.

128213928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080 (or 1067 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 128213928 is about 11323.1589231981. The cubic root of 128213928 is about 504.2490265955.

The spelling of 128213928 in words is "one hundred twenty-eight million, two hundred thirteen thousand, nine hundred twenty-eight".