998939881 has 2 divisors, whose sum is σ = 998939882. Its totient is φ = 998939880.

The previous prime is 998939863. The next prime is 998939899. The reversal of 998939881 is 188939899.

It is a balanced prime because it is at equal distance from previous prime (998939863) and next prime (998939899).

It can be written as a sum of positive squares in only one way, i.e., 662547600 + 336392281 = 25740^2 + 18341^2 .

It is an emirp because it is prime and its reverse (188939899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998939881 - 2⁵ = 998939849 is a prime.

It is a super-2 number, since 2×998939881² = 1995761771704588322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (998939831) 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 as a sum of consecutive naturals, namely, 499469940 + 499469941.

It is an arithmetic number, because the mean of its divisors is an integer number (499469941).

Almost surely, 2^998939881 is an apocalyptic number.

It is an amenable number.

998939881 is a deficient number, since it is larger than the sum of its proper divisors (1).

998939881 is an equidigital number, since it uses as much as digits as its factorization.

998939881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10077696, while the sum is 64.

The square root of 998939881 is about 31606.0102037571. The cubic root of 998939881 is about 999.6465020539.

The spelling of 998939881 in words is "nine hundred ninety-eight million, nine hundred thirty-nine thousand, eight hundred eighty-one".