31290613 has 2 divisors, whose sum is σ = 31290614. Its totient is φ = 31290612.

The previous prime is 31290601. The next prime is 31290629. The reversal of 31290613 is 31609213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28708164 + 2582449 = 5358^2 + 1607^2 .

It is an emirp because it is prime and its reverse (31609213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31290613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31290653) 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, 15645306 + 15645307.

It is an arithmetic number, because the mean of its divisors is an integer number (15645307).

Almost surely, 2^31290613 is an apocalyptic number.

It is an amenable number.

31290613 is a deficient number, since it is larger than the sum of its proper divisors (1).

31290613 is an equidigital number, since it uses as much as digits as its factorization.

31290613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 31290613 is about 5593.8013014407. The cubic root of 31290613 is about 315.1166545346.

Adding to 31290613 its reverse (31609213), we get a palindrome (62899826).

The spelling of 31290613 in words is "thirty-one million, two hundred ninety thousand, six hundred thirteen".