31132220 has 48 divisors (see below), whose sum is σ = 75855360. Its totient is φ = 10511424.

The previous prime is 31132201. The next prime is 31132223. The reversal of 31132220 is 2223113.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 31132195 and 31132204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31132223) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 7721 + ... + 11039.

It is an arithmetic number, because the mean of its divisors is an integer number (1580320).

Almost surely, 2^31132220 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 31132220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37927680).

31132220 is an abundant number, since it is smaller than the sum of its proper divisors (44723140).

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

31132220 is a wasteful number, since it uses less digits than its factorization.

31132220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3402 (or 3400 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 31132220 is about 5579.6254354571. The cubic root of 31132220 is about 314.5840482809.

Adding to 31132220 its reverse (2223113), we get a palindrome (33355333).

The spelling of 31132220 in words is "thirty-one million, one hundred thirty-two thousand, two hundred twenty".