998818557 has 32 divisors (see below), whose sum is σ = 1487185920. Its totient is φ = 591192000.

The previous prime is 998818553. The next prime is 998818591. The reversal of 998818557 is 755818899.

It is not a de Polignac number, because 998818557 - 2² = 998818553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 998818557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998818553) 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 in 31 ways as a sum of consecutive naturals, for example, 253432 + ... + 257342.

It is an arithmetic number, because the mean of its divisors is an integer number (46474560).

Almost surely, 2^998818557 is an apocalyptic number.

It is an amenable number.

998818557 is a deficient number, since it is larger than the sum of its proper divisors (488367363).

998818557 is a wasteful number, since it uses less digits than its factorization.

998818557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4105.

The product of its digits is 7257600, while the sum is 60.

The square root of 998818557 is about 31604.0908269800. The cubic root of 998818557 is about 999.6060304751.

The spelling of 998818557 in words is "nine hundred ninety-eight million, eight hundred eighteen thousand, five hundred fifty-seven".