39945603617 has 2 divisors, whose sum is σ = 39945603618. Its totient is φ = 39945603616.

The previous prime is 39945603587. The next prime is 39945603637. The reversal of 39945603617 is 71630654993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34933105216 + 5012498401 = 186904^2 + 70799^2 .

It is an emirp because it is prime and its reverse (71630654993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39945603617 - 2⁸ = 39945603361 is a prime.

It is not a weakly prime, because it can be changed into another prime (39945603637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19972801808 + 19972801809.

It is an arithmetic number, because the mean of its divisors is an integer number (19972801809).

Almost surely, 2^39945603617 is an apocalyptic number.

It is an amenable number.

39945603617 is a deficient number, since it is larger than the sum of its proper divisors (1).

39945603617 is an equidigital number, since it uses as much as digits as its factorization.

39945603617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3674160, while the sum is 53.

The spelling of 39945603617 in words is "thirty-nine billion, nine hundred forty-five million, six hundred three thousand, six hundred seventeen".