9999971 has 2 divisors, whose sum is σ = 9999972. Its totient is φ = 9999970.

The previous prime is 9999943. The next prime is 9999973. The reversal of 9999971 is 1799999.

It is a strong prime.

It is an emirp because it is prime and its reverse (1799999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9999971 - 2⁶ = 9999907 is a prime.

Together with 9999973, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (9999973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999985 + 4999986.

It is an arithmetic number, because the mean of its divisors is an integer number (4999986).

Almost surely, 2^9999971 is an apocalyptic number.

9999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999971 is an equidigital number, since it uses as much as digits as its factorization.

9999971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 413343, while the sum is 53.

The square root of 9999971 is about 3162.2730748624. The cubic root of 9999971 is about 215.4432607410.

The spelling of 9999971 in words is "nine million, nine hundred ninety-nine thousand, nine hundred seventy-one".