31128328 has 48 divisors (see below), whose sum is σ = 74077200. Its totient is φ = 12126240.

The previous prime is 31128323. The next prime is 31128379. The reversal of 31128328 is 82382113.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 31128296 and 31128305.

It is not an unprimeable number, because it can be changed into a prime (31128323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 703 + ... + 7921.

It is an arithmetic number, because the mean of its divisors is an integer number (1543275).

Almost surely, 2^31128328 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 31128328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37038600).

31128328 is an abundant number, since it is smaller than the sum of its proper divisors (42948872).

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

31128328 is a wasteful number, since it uses less digits than its factorization.

31128328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7250 (or 7239 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 31128328 is about 5579.2766556248. The cubic root of 31128328 is about 314.5709384744.

The spelling of 31128328 in words is "thirty-one million, one hundred twenty-eight thousand, three hundred twenty-eight".