998817139 has 2 divisors, whose sum is σ = 998817140. Its totient is φ = 998817138.

The previous prime is 998817107. The next prime is 998817143. The reversal of 998817139 is 931718899.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 998817139 - 2⁵ = 998817107 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 998817139.

It is not a weakly prime, because it can be changed into another prime (998817199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499408569 + 499408570.

It is an arithmetic number, because the mean of its divisors is an integer number (499408570).

Almost surely, 2^998817139 is an apocalyptic number.

998817139 is a deficient number, since it is larger than the sum of its proper divisors (1).

998817139 is an equidigital number, since it uses as much as digits as its factorization.

998817139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 55.

The square root of 998817139 is about 31604.0683931674. The cubic root of 998817139 is about 999.6055574355.

The spelling of 998817139 in words is "nine hundred ninety-eight million, eight hundred seventeen thousand, one hundred thirty-nine".