8998991 has 2 divisors, whose sum is σ = 8998992. Its totient is φ = 8998990.

The previous prime is 8998987. The next prime is 8999009. The reversal of 8998991 is 1998998.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8998991 - 2² = 8998987 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8998901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4499495 + 4499496.

It is an arithmetic number, because the mean of its divisors is an integer number (4499496).

Almost surely, 2^8998991 is an apocalyptic number.

8998991 is a deficient number, since it is larger than the sum of its proper divisors (1).

8998991 is an equidigital number, since it uses as much as digits as its factorization.

8998991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 53.

The square root of 8998991 is about 2999.8318286197. The cubic root of 8998991 is about 208.0006086644. Note that the first 3 decimals are identical.

The spelling of 8998991 in words is "eight million, nine hundred ninety-eight thousand, nine hundred ninety-one".