998915993 has 2 divisors, whose sum is σ = 998915994. Its totient is φ = 998915992.

The previous prime is 998915987. The next prime is 998916019. The reversal of 998915993 is 399519899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 959326729 + 39589264 = 30973^2 + 6292^2 .

It is a cyclic number.

It is not a de Polignac number, because 998915993 - 2⁴ = 998915977 is a prime.

It is a super-2 number, since 2×998915993² = 1995666322142352098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (998918993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499457996 + 499457997.

It is an arithmetic number, because the mean of its divisors is an integer number (499457997).

Almost surely, 2^998915993 is an apocalyptic number.

It is an amenable number.

998915993 is a deficient number, since it is larger than the sum of its proper divisors (1).

998915993 is an equidigital number, since it uses as much as digits as its factorization.

998915993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7085880, while the sum is 62.

The square root of 998915993 is about 31605.6322986901. The cubic root of 998915993 is about 999.6385336912.

The spelling of 998915993 in words is "nine hundred ninety-eight million, nine hundred fifteen thousand, nine hundred ninety-three".