998511491 has 2 divisors, whose sum is σ = 998511492. Its totient is φ = 998511490.

The previous prime is 998511421. The next prime is 998511517. The reversal of 998511491 is 194115899.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 998511491 - 2¹⁴ = 998495107 is a prime.

It is not a weakly prime, because it can be changed into another prime (998511401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499255745 + 499255746.

It is an arithmetic number, because the mean of its divisors is an integer number (499255746).

Almost surely, 2^998511491 is an apocalyptic number.

998511491 is a deficient number, since it is larger than the sum of its proper divisors (1).

998511491 is an equidigital number, since it uses as much as digits as its factorization.

998511491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 47.

The square root of 998511491 is about 31599.2324432098. The cubic root of 998511491 is about 999.5035839452.

The spelling of 998511491 in words is "nine hundred ninety-eight million, five hundred eleven thousand, four hundred ninety-one".