999988886681 has 2 divisors, whose sum is σ = 999988886682. Its totient is φ = 999988886680.

The previous prime is 999988886569. The next prime is 999988886717. The reversal of 999988886681 is 186688889999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 997819190281 + 2169696400 = 998909^2 + 46580^2 .

It is a cyclic number.

It is not a de Polignac number, because 999988886681 - 2²⁶ = 999921777817 is a prime.

It is a super-2 number, since 2×999988886681² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (999988886081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499994443340 + 499994443341.

It is an arithmetic number, because the mean of its divisors is an integer number (499994443341).

Almost surely, 2^999988886681 is an apocalyptic number.

It is an amenable number.

999988886681 is a deficient number, since it is larger than the sum of its proper divisors (1).

999988886681 is an equidigital number, since it uses as much as digits as its factorization.

999988886681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7739670528, while the sum is 89.

The spelling of 999988886681 in words is "nine hundred ninety-nine billion, nine hundred eighty-eight million, eight hundred eighty-six thousand, six hundred eighty-one".