31131222 has 16 divisors (see below), whose sum is σ = 62845632. Its totient is φ = 10279880.

The previous prime is 31131211. The next prime is 31131227. The reversal of 31131222 is 22213113.

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 (31131227) 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 7 ways as a sum of consecutive naturals, for example, 23604 + ... + 24887.

It is an arithmetic number, because the mean of its divisors is an integer number (3927852).

Almost surely, 2^31131222 is an apocalyptic number.

31131222 is an abundant number, since it is smaller than the sum of its proper divisors (31714410).

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

31131222 is a wasteful number, since it uses less digits than its factorization.

31131222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48603.

The product of its digits is 72, while the sum is 15.

The square root of 31131222 is about 5579.5360022138. The cubic root of 31131222 is about 314.5806867234.

Adding to 31131222 its reverse (22213113), we get a palindrome (53344335).

The spelling of 31131222 in words is "thirty-one million, one hundred thirty-one thousand, two hundred twenty-two".