998999971 has 2 divisors, whose sum is σ = 998999972. Its totient is φ = 998999970.

The previous prime is 998999957. The next prime is 998999999. The reversal of 998999971 is 179999899.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998999971 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 998999971.

It is not a weakly prime, because it can be changed into another prime (998999941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499499985 + 499499986.

It is an arithmetic number, because the mean of its divisors is an integer number (499499986).

Almost surely, 2^998999971 is an apocalyptic number.

998999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

998999971 is an equidigital number, since it uses as much as digits as its factorization.

998999971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29760696, while the sum is 70.

The square root of 998999971 is about 31606.9607997985. The cubic root of 998999971 is about 999.6665458207. Note that the first 3 decimals are identical.

The spelling of 998999971 in words is "nine hundred ninety-eight million, nine hundred ninety-nine thousand, nine hundred seventy-one".