31128216 has 128 divisors (see below), whose sum is σ = 94617600. Its totient is φ = 8346240.

The previous prime is 31128203. The next prime is 31128217. The reversal of 31128216 is 61282113.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31128217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 223875 + ... + 224013.

It is an arithmetic number, because the mean of its divisors is an integer number (739200).

Almost surely, 2^31128216 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 31128216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47308800).

31128216 is an abundant number, since it is smaller than the sum of its proper divisors (63489384).

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

31128216 is a wasteful number, since it uses less digits than its factorization.

31128216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229 (or 225 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 31128216 is about 5579.2666184724. The cubic root of 31128216 is about 314.5705611976.

The spelling of 31128216 in words is "thirty-one million, one hundred twenty-eight thousand, two hundred sixteen".