39845837609 has 2 divisors, whose sum is σ = 39845837610. Its totient is φ = 39845837608.

The previous prime is 39845837599. The next prime is 39845837611. The reversal of 39845837609 is 90673854893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39819005209 + 26832400 = 199547^2 + 5180^2 .

It is an emirp because it is prime and its reverse (90673854893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39845837609 - 2¹⁶ = 39845772073 is a prime.

Together with 39845837611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39845837909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19922918804 + 19922918805.

It is an arithmetic number, because the mean of its divisors is an integer number (19922918805).

Almost surely, 2^39845837609 is an apocalyptic number.

It is an amenable number.

39845837609 is a deficient number, since it is larger than the sum of its proper divisors (1).

39845837609 is an equidigital number, since it uses as much as digits as its factorization.

39845837609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39191040, while the sum is 62.

The spelling of 39845837609 in words is "thirty-nine billion, eight hundred forty-five million, eight hundred thirty-seven thousand, six hundred nine".