998910931 has 2 divisors, whose sum is σ = 998910932. Its totient is φ = 998910930.

The previous prime is 998910917. The next prime is 998910943. The reversal of 998910931 is 139019899.

It is a strong prime.

It is an emirp because it is prime and its reverse (139019899) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998910931 is a prime.

It is a super-2 number, since 2×998910931² = 1995646096142573522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (998910901) 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, 499455465 + 499455466.

It is an arithmetic number, because the mean of its divisors is an integer number (499455466).

Almost surely, 2^998910931 is an apocalyptic number.

998910931 is a deficient number, since it is larger than the sum of its proper divisors (1).

998910931 is an equidigital number, since it uses as much as digits as its factorization.

998910931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 49.

The square root of 998910931 is about 31605.5522179253. The cubic root of 998910931 is about 999.6368451345.

The spelling of 998910931 in words is "nine hundred ninety-eight million, nine hundred ten thousand, nine hundred thirty-one".