9837985521601 has 2 divisors, whose sum is σ = 9837985521602. Its totient is φ = 9837985521600.

The previous prime is 9837985521599. The next prime is 9837985521607. The reversal of 9837985521601 is 1061255897389.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5779211192001 + 4058774329600 = 2403999^2 + 2014640^2 .

It is a cyclic number.

It is not a de Polignac number, because 9837985521601 - 2¹ = 9837985521599 is a prime.

Together with 9837985521599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (9837985521607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4918992760800 + 4918992760801.

It is an arithmetic number, because the mean of its divisors is an integer number (4918992760801).

Almost surely, 2^{9837985521601} is an apocalyptic number.

It is an amenable number.

9837985521601 is a deficient number, since it is larger than the sum of its proper divisors (1).

9837985521601 is an equidigital number, since it uses as much as digits as its factorization.

9837985521601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32659200, while the sum is 64.

The spelling of 9837985521601 in words is "nine trillion, eight hundred thirty-seven billion, nine hundred eighty-five million, five hundred twenty-one thousand, six hundred one".