31102213 has 2 divisors, whose sum is σ = 31102214. Its totient is φ = 31102212.

The previous prime is 31102199. The next prime is 31102219. The reversal of 31102213 is 31220113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 10870209 = 4498^2 + 3297^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31102213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31102193 and 31102202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31102219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15551106 + 15551107.

It is an arithmetic number, because the mean of its divisors is an integer number (15551107).

Almost surely, 2^31102213 is an apocalyptic number.

It is an amenable number.

31102213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31102213 is an equidigital number, since it uses as much as digits as its factorization.

31102213 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 31102213 is about 5576.9358074125. The cubic root of 31102213 is about 314.4829444726.

Adding to 31102213 its reverse (31220113), we get a palindrome (62322326).

The spelling of 31102213 in words is "thirty-one million, one hundred two thousand, two hundred thirteen".