999911888116649 has 2 divisors, whose sum is σ = 999911888116650. Its totient is φ = 999911888116648.

The previous prime is 999911888116621. The next prime is 999911888116657. The reversal of 999911888116649 is 946611888119999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 789585553189225 + 210326334927424 = 28099565^2 + 14502632^2 .

It is a cyclic number.

It is not a de Polignac number, because 999911888116649 - 2¹⁶ = 999911888051113 is a prime.

It is not a weakly prime, because it can be changed into another prime (999911888116619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499955944058324 + 499955944058325.

It is an arithmetic number, because the mean of its divisors is an integer number (499955944058325).

Almost surely, 2^{999911888116649} is an apocalyptic number.

It is an amenable number.

999911888116649 is a deficient number, since it is larger than the sum of its proper divisors (1).

999911888116649 is an equidigital number, since it uses as much as digits as its factorization.

999911888116649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4353564672, while the sum is 89.

The spelling of 999911888116649 in words is "nine hundred ninety-nine trillion, nine hundred eleven billion, eight hundred eighty-eight million, one hundred sixteen thousand, six hundred forty-nine".