31719013 has 2 divisors, whose sum is σ = 31719014. Its totient is φ = 31719012.

The previous prime is 31719007. The next prime is 31719029. The reversal of 31719013 is 31091713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27384289 + 4334724 = 5233^2 + 2082^2 .

It is an emirp because it is prime and its reverse (31091713) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31719013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31719043) 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, 15859506 + 15859507.

It is an arithmetic number, because the mean of its divisors is an integer number (15859507).

Almost surely, 2^31719013 is an apocalyptic number.

It is an amenable number.

31719013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31719013 is an equidigital number, since it uses as much as digits as its factorization.

31719013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 567, while the sum is 25.

The square root of 31719013 is about 5631.9635119557. The cubic root of 31719013 is about 316.5482291463.

It can be divided in two parts, 3171901 and 3, that multiplied together give a triangular number (9515703 = T₄₃₆₂).

The spelling of 31719013 in words is "thirty-one million, seven hundred nineteen thousand, thirteen".