72128140 has 48 divisors (see below), whose sum is σ = 174855744. Its totient is φ = 24480000.

The previous prime is 72128131. The next prime is 72128141. The reversal of 72128140 is 4182127.

It is a happy number.

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (72128141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11590 + ... + 16690.

It is an arithmetic number, because the mean of its divisors is an integer number (3642828).

Almost surely, 2^72128140 is an apocalyptic number.

72128140 is a gapful number since it is divisible by the number (70) 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 72128140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87427872).

72128140 is an abundant number, since it is smaller than the sum of its proper divisors (102727604).

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

72128140 is a wasteful number, since it uses less digits than its factorization.

72128140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5218 (or 5216 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 72128140 is about 8492.8287395897. The cubic root of 72128140 is about 416.2634164379.

The spelling of 72128140 in words is "seventy-two million, one hundred twenty-eight thousand, one hundred forty".