31230220 has 48 divisors (see below), whose sum is σ = 76991040. Its totient is φ = 10416384.

The previous prime is 31230211. The next prime is 31230223. The reversal of 31230220 is 2203213.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 31230220.

It is not an unprimeable number, because it can be changed into a prime (31230223) 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, 2166 + ... + 8194.

It is an arithmetic number, because the mean of its divisors is an integer number (1603980).

Almost surely, 2^31230220 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 31230220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38495520).

31230220 is an abundant number, since it is smaller than the sum of its proper divisors (45760820).

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

31230220 is a wasteful number, since it uses less digits than its factorization.

31230220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6082 (or 6080 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 31230220 is about 5588.4004867225. The cubic root of 31230220 is about 314.9137918117.

Adding to 31230220 its reverse (2203213), we get a palindrome (33433433).

The spelling of 31230220 in words is "thirty-one million, two hundred thirty thousand, two hundred twenty".