998597993 has 2 divisors, whose sum is σ = 998597994. Its totient is φ = 998597992.

The previous prime is 998597989. The next prime is 998598047. The reversal of 998597993 is 399795899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 985143769 + 13454224 = 31387^2 + 3668^2 .

It is a cyclic number.

It is not a de Polignac number, because 998597993 - 2² = 998597989 is a prime.

It is not a weakly prime, because it can be changed into another prime (998597903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499298996 + 499298997.

It is an arithmetic number, because the mean of its divisors is an integer number (499298997).

Almost surely, 2^998597993 is an apocalyptic number.

It is an amenable number.

998597993 is a deficient number, since it is larger than the sum of its proper divisors (1).

998597993 is an equidigital number, since it uses as much as digits as its factorization.

998597993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49601160, while the sum is 68.

The square root of 998597993 is about 31600.6011493452. The cubic root of 998597993 is about 999.5324457604.

The spelling of 998597993 in words is "nine hundred ninety-eight million, five hundred ninety-seven thousand, nine hundred ninety-three".