39518981861 has 2 divisors, whose sum is σ = 39518981862. Its totient is φ = 39518981860.

The previous prime is 39518981807. The next prime is 39518981911. The reversal of 39518981861 is 16818981593.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33344951236 + 6174030625 = 182606^2 + 78575^2 .

It is a cyclic number.

It is not a de Polignac number, because 39518981861 - 2¹⁴ = 39518965477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39518981861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39518981261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19759490930 + 19759490931.

It is an arithmetic number, because the mean of its divisors is an integer number (19759490931).

Almost surely, 2^39518981861 is an apocalyptic number.

It is an amenable number.

39518981861 is a deficient number, since it is larger than the sum of its proper divisors (1).

39518981861 is an equidigital number, since it uses as much as digits as its factorization.

39518981861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3732480, while the sum is 59.

The spelling of 39518981861 in words is "thirty-nine billion, five hundred eighteen million, nine hundred eighty-one thousand, eight hundred sixty-one".