999997871 has 2 divisors, whose sum is σ = 999997872. Its totient is φ = 999997870.

The previous prime is 999997811. The next prime is 999997891. The reversal of 999997871 is 178799999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999997871 - 2¹⁴ = 999981487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999997811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499998935 + 499998936.

It is an arithmetic number, because the mean of its divisors is an integer number (499998936).

Almost surely, 2^999997871 is an apocalyptic number.

999997871 is a deficient number, since it is larger than the sum of its proper divisors (1).

999997871 is an equidigital number, since it uses as much as digits as its factorization.

999997871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23147208, while the sum is 68.

The square root of 999997871 is about 31622.7429392202. The cubic root of 999997871 is about 999.9992903328. Note that the first 3 decimals are identical.

The spelling of 999997871 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, eight hundred seventy-one".