31225213 has 2 divisors, whose sum is σ = 31225214. Its totient is φ = 31225212.

The previous prime is 31225169. The next prime is 31225247. The reversal of 31225213 is 31252213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30052324 + 1172889 = 5482^2 + 1083^2 .

It is a cyclic number.

It is not a de Polignac number, because 31225213 - 2⁹ = 31224701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31225273) 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 as a sum of consecutive naturals, namely, 15612606 + 15612607.

It is an arithmetic number, because the mean of its divisors is an integer number (15612607).

Almost surely, 2^31225213 is an apocalyptic number.

It is an amenable number.

31225213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31225213 is an equidigital number, since it uses as much as digits as its factorization.

31225213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 19.

The square root of 31225213 is about 5587.9524872712. The cubic root of 31225213 is about 314.8969613440.

Adding to 31225213 its reverse (31252213), we get a palindrome (62477426).

Subtracting 31225213 from its reverse (31252213), we obtain a cube (27000 = 30³).

The spelling of 31225213 in words is "thirty-one million, two hundred twenty-five thousand, two hundred thirteen".