31280228 has 30 divisors (see below), whose sum is σ = 63879606. Its totient is φ = 13401696.

The previous prime is 31280219. The next prime is 31280231. The reversal of 31280228 is 82208213.

It can be written as a sum of positive squares in only one way, i.e., 30118144 + 1162084 = 5488^2 + 1078^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 31280197 and 31280206.

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 9 ways as a sum of consecutive naturals, for example, 7976 + ... + 11232.

Almost surely, 2^31280228 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 31280228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31939803).

31280228 is an abundant number, since it is smaller than the sum of its proper divisors (32599378).

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

31280228 is an equidigital number, since it uses as much as digits as its factorization.

31280228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3289 (or 3266 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 31280228 is about 5592.8729647651. The cubic root of 31280228 is about 315.0817894612.

The spelling of 31280228 in words is "thirty-one million, two hundred eighty thousand, two hundred twenty-eight".