998239961 has 2 divisors, whose sum is σ = 998239962. Its totient is φ = 998239960.

The previous prime is 998239937. The next prime is 998239967. The reversal of 998239961 is 169932899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 559086025 + 439153936 = 23645^2 + 20956^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998239961 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 998239897 and 998239906.

It is not a weakly prime, because it can be changed into another prime (998239967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499119980 + 499119981.

It is an arithmetic number, because the mean of its divisors is an integer number (499119981).

Almost surely, 2^998239961 is an apocalyptic number.

It is an amenable number.

998239961 is a deficient number, since it is larger than the sum of its proper divisors (1).

998239961 is an equidigital number, since it uses as much as digits as its factorization.

998239961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1889568, while the sum is 56.

The square root of 998239961 is about 31594.9356859608. The cubic root of 998239961 is about 999.4129758034.

The spelling of 998239961 in words is "nine hundred ninety-eight million, two hundred thirty-nine thousand, nine hundred sixty-one".