31217225 has 12 divisors (see below), whose sum is σ = 41687436. Its totient is φ = 23052480.

The previous prime is 31217203. The next prime is 31217261. The reversal of 31217225 is 52271213.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 4787344 + 26429881 = 2188^2 + 5141^2 .

It is not a de Polignac number, because 31217225 - 2¹² = 31213129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31217225.

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 11 ways as a sum of consecutive naturals, for example, 47702 + ... + 48351.

It is an arithmetic number, because the mean of its divisors is an integer number (3473953).

Almost surely, 2^31217225 is an apocalyptic number.

It is an amenable number.

31217225 is a deficient number, since it is larger than the sum of its proper divisors (10470211).

31217225 is a wasteful number, since it uses less digits than its factorization.

31217225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96076 (or 96071 counting only the distinct ones).

The product of its digits is 840, while the sum is 23.

The square root of 31217225 is about 5587.2376895922. The cubic root of 31217225 is about 314.8701068546.

Adding to 31217225 its reverse (52271213), we get a palindrome (83488438).

The spelling of 31217225 in words is "thirty-one million, two hundred seventeen thousand, two hundred twenty-five".