9999993999971 has 2 divisors, whose sum is σ = 9999993999972. Its totient is φ = 9999993999970.

The previous prime is 9999993999967. The next prime is 9999993999973. The reversal of 9999993999971 is 1799993999999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9999993999971 - 2² = 9999993999967 is a prime.

Together with 9999993999973, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9999993999973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999996999985 + 4999996999986.

It is an arithmetic number, because the mean of its divisors is an integer number (4999996999986).

Almost surely, 2^{9999993999971} is an apocalyptic number.

9999993999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999993999971 is an equidigital number, since it uses as much as digits as its factorization.

9999993999971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 73222472421, while the sum is 101.

The spelling of 9999993999971 in words is "nine trillion, nine hundred ninety-nine billion, nine hundred ninety-three million, nine hundred ninety-nine thousand, nine hundred seventy-one".