31120213 has 2 divisors, whose sum is σ = 31120214. Its totient is φ = 31120212.

The previous prime is 31120211. The next prime is 31120231. The reversal of 31120213 is 31202113.

Together with next prime (31120231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21921124 + 9199089 = 4682^2 + 3033^2 .

It is a cyclic number.

It is not a de Polignac number, because 31120213 - 2¹ = 31120211 is a prime.

Together with 31120211, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 31120193 and 31120202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31120211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560106 + 15560107.

It is an arithmetic number, because the mean of its divisors is an integer number (15560107).

Almost surely, 2^31120213 is an apocalyptic number.

It is an amenable number.

31120213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31120213 is an equidigital number, since it uses as much as digits as its factorization.

31120213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 31120213 is about 5578.5493634098. The cubic root of 31120213 is about 314.5436004065.

Adding to 31120213 its reverse (31202113), we get a palindrome (62322326).

The spelling of 31120213 in words is "thirty-one million, one hundred twenty thousand, two hundred thirteen".