998977961 has 2 divisors, whose sum is σ = 998977962. Its totient is φ = 998977960.

The previous prime is 998977943. The next prime is 998977979. The reversal of 998977961 is 169779899.

It is a balanced prime because it is at equal distance from previous prime (998977943) and next prime (998977979).

It can be written as a sum of positive squares in only one way, i.e., 814017961 + 184960000 = 28531^2 + 13600^2 .

It is an emirp because it is prime and its reverse (169779899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998977961 - 2⁶ = 998977897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (998977901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499488980 + 499488981.

It is an arithmetic number, because the mean of its divisors is an integer number (499488981).

Almost surely, 2^998977961 is an apocalyptic number.

It is an amenable number.

998977961 is a deficient number, since it is larger than the sum of its proper divisors (1).

998977961 is an equidigital number, since it uses as much as digits as its factorization.

998977961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15431472, while the sum is 65.

The square root of 998977961 is about 31606.6126150842. The cubic root of 998977961 is about 999.6592042048.

The spelling of 998977961 in words is "nine hundred ninety-eight million, nine hundred seventy-seven thousand, nine hundred sixty-one".