9994519510921 has 81 divisors (see below), whose sum is σ = 11600488095399. Its totient is φ = 8604096177600.

The previous prime is 9994519510861. The next prime is 9994519510957. The reversal of 9994519510921 is 1290159154999.

It is a happy number.

The square root of 9994519510921 is 3161411.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5673376153225 + 4321143357696 = 2381885^2 + 2078736^2 .

It is not a de Polignac number, because 9994519510921 - 2¹¹ = 9994519508873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9994519519921) 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 in 80 ways as a sum of consecutive naturals, for example, 78697003960 + ... + 78697004086.

Almost surely, 2^{9994519510921} is an apocalyptic number.

9994519510921 is the 3161411-st square number.

9994519510921 is the 1580706-th centered octagonal number.

It is an amenable number.

9994519510921 is a deficient number, since it is larger than the sum of its proper divisors (1605968584478).

9994519510921 is an equidigital number, since it uses as much as digits as its factorization.

9994519510921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 11809800, while the sum is 64.

Multiplying 9994519510921 by its sum of digits (64), we get a square (639649248698944 = 25291288²).

The spelling of 9994519510921 in words is "nine trillion, nine hundred ninety-four billion, five hundred nineteen million, five hundred ten thousand, nine hundred twenty-one".