128215740 has 72 divisors (see below), whose sum is σ = 364897008. Its totient is φ = 33638400.

The previous prime is 128215709. The next prime is 128215793. The reversal of 128215740 is 47512821.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 128215698 and 128215707.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 319540 + ... + 319940.

It is an arithmetic number, because the mean of its divisors is an integer number (5068014).

Almost surely, 2^128215740 is an apocalyptic number.

128215740 is a gapful number since it is divisible by the number (10) 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 128215740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182448504).

128215740 is an abundant number, since it is smaller than the sum of its proper divisors (236681268).

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

128215740 is a wasteful number, since it uses less digits than its factorization.

128215740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 128215740 is about 11323.2389359229. The cubic root of 128215740 is about 504.2514020392.

The spelling of 128215740 in words is "one hundred twenty-eight million, two hundred fifteen thousand, seven hundred forty".