999998971 has 2 divisors, whose sum is σ = 999998972. Its totient is φ = 999998970.

The previous prime is 999998959. The next prime is 999998981. The reversal of 999998971 is 179899999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999998971 - 2⁷ = 999998843 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 999998971.

It is not a weakly prime, because it can be changed into another prime (999998921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999485 + 499999486.

It is an arithmetic number, because the mean of its divisors is an integer number (499999486).

Almost surely, 2^999998971 is an apocalyptic number.

999998971 is a deficient number, since it is larger than the sum of its proper divisors (1).

999998971 is an equidigital number, since it uses as much as digits as its factorization.

999998971 is an evil number, because the sum of its binary digits is even.

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

The square root of 999998971 is about 31622.7603317610. The cubic root of 999998971 is about 999.9996569999. Note that the first 3 decimals are identical.

The spelling of 999998971 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, nine hundred seventy-one".