39720613 has 2 divisors, whose sum is σ = 39720614. Its totient is φ = 39720612.

The previous prime is 39720607. The next prime is 39720617. The reversal of 39720613 is 31602793.

39720613 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36505764 + 3214849 = 6042^2 + 1793^2 .

It is an emirp because it is prime and its reverse (31602793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39720613 - 2²¹ = 37623461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39720617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19860306 + 19860307.

It is an arithmetic number, because the mean of its divisors is an integer number (19860307).

Almost surely, 2^39720613 is an apocalyptic number.

It is an amenable number.

39720613 is a deficient number, since it is larger than the sum of its proper divisors (1).

39720613 is an equidigital number, since it uses as much as digits as its factorization.

39720613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 39720613 is about 6302.4291348654. The cubic root of 39720613 is about 341.1970865285.

The spelling of 39720613 in words is "thirty-nine million, seven hundred twenty thousand, six hundred thirteen".