31212113 has 2 divisors, whose sum is σ = 31212114. Its totient is φ = 31212112.

The previous prime is 31212061. The next prime is 31212143. The reversal of 31212113 is 31121213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17581249 + 13630864 = 4193^2 + 3692^2 .

It is a cyclic number.

It is not a de Polignac number, because 31212113 - 2⁸ = 31211857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31212143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606056 + 15606057.

It is an arithmetic number, because the mean of its divisors is an integer number (15606057).

Almost surely, 2^31212113 is an apocalyptic number.

It is an amenable number.

31212113 is a deficient number, since it is larger than the sum of its proper divisors (1).

31212113 is an equidigital number, since it uses as much as digits as its factorization.

31212113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36, while the sum is 14.

The square root of 31212113 is about 5586.7801997215. The cubic root of 31212113 is about 314.8529186531.

Adding to 31212113 its reverse (31121213), we get a palindrome (62333326).

The spelling of 31212113 in words is "thirty-one million, two hundred twelve thousand, one hundred thirteen".