31125222 has 40 divisors (see below), whose sum is σ = 70131600. Its totient is φ = 10317456.

The previous prime is 31125221. The next prime is 31125239. The reversal of 31125222 is 22252113.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31125195 and 31125204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31125221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 36679 + ... + 37517.

It is an arithmetic number, because the mean of its divisors is an integer number (1753290).

Almost surely, 2^31125222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31125222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35065800).

31125222 is an abundant number, since it is smaller than the sum of its proper divisors (39006378).

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

31125222 is a wasteful number, since it uses less digits than its factorization.

31125222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082 (or 1073 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 31125222 is about 5578.9982971856. The cubic root of 31125222 is about 314.5604754449.

Adding to 31125222 its reverse (22252113), we get a palindrome (53377335).

The spelling of 31125222 in words is "thirty-one million, one hundred twenty-five thousand, two hundred twenty-two".