31121413 has 2 divisors, whose sum is σ = 31121414. Its totient is φ = 31121412.

The previous prime is 31121401. The next prime is 31121479. The reversal of 31121413 is 31412113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20052484 + 11068929 = 4478^2 + 3327^2 .

It is a cyclic number.

It is not a de Polignac number, because 31121413 - 2⁵ = 31121381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31121483) 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, 15560706 + 15560707.

It is an arithmetic number, because the mean of its divisors is an integer number (15560707).

Almost surely, 2^31121413 is an apocalyptic number.

It is an amenable number.

31121413 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121413 is an equidigital number, since it uses as much as digits as its factorization.

31121413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 16.

The square root of 31121413 is about 5578.6569172158. The cubic root of 31121413 is about 314.5476433038.

Adding to 31121413 its reverse (31412113), we get a palindrome (62533526).

The spelling of 31121413 in words is "thirty-one million, one hundred twenty-one thousand, four hundred thirteen".