996721961 has 2 divisors, whose sum is σ = 996721962. Its totient is φ = 996721960.

The previous prime is 996721939. The next prime is 996721963. The reversal of 996721961 is 169127699.

996721961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 658897561 + 337824400 = 25669^2 + 18380^2 .

It is a cyclic number.

It is not a de Polignac number, because 996721961 - 2¹⁸ = 996459817 is a prime.

Together with 996721963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (996721963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498360980 + 498360981.

It is an arithmetic number, because the mean of its divisors is an integer number (498360981).

Almost surely, 2^996721961 is an apocalyptic number.

It is an amenable number.

996721961 is a deficient number, since it is larger than the sum of its proper divisors (1).

996721961 is an equidigital number, since it uses as much as digits as its factorization.

996721961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 50.

The square root of 996721961 is about 31570.9037089533. The cubic root of 996721961 is about 998.9061242054.

The spelling of 996721961 in words is "nine hundred ninety-six million, seven hundred twenty-one thousand, nine hundred sixty-one".