998626891 has 2 divisors, whose sum is σ = 998626892. Its totient is φ = 998626890.

The previous prime is 998626879. The next prime is 998626957. The reversal of 998626891 is 198626899.

It is a weak prime.

It is an emirp because it is prime and its reverse (198626899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998626891 - 2¹⁹ = 998102603 is a prime.

It is not a weakly prime, because it can be changed into another prime (998626841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499313445 + 499313446.

It is an arithmetic number, because the mean of its divisors is an integer number (499313446).

Almost surely, 2^998626891 is an apocalyptic number.

998626891 is a deficient number, since it is larger than the sum of its proper divisors (1).

998626891 is an equidigital number, since it uses as much as digits as its factorization.

998626891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 58.

The square root of 998626891 is about 31601.0583841744. The cubic root of 998626891 is about 999.5420873480.

The spelling of 998626891 in words is "nine hundred ninety-eight million, six hundred twenty-six thousand, eight hundred ninety-one".