997961 has 2 divisors, whose sum is σ = 997962. Its totient is φ = 997960.

The previous prime is 997949. The next prime is 997963. The reversal of 997961 is 169799.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 732736 + 265225 = 856^2 + 515^2 .

It is a cyclic number.

It is not a de Polignac number, because 997961 - 2⁶ = 997897 is a prime.

Together with 997963, 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 (997963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498980 + 498981.

It is an arithmetic number, because the mean of its divisors is an integer number (498981).

2⁹⁹⁷⁹⁶¹ is an apocalyptic number.

It is an amenable number.

997961 is a deficient number, since it is larger than the sum of its proper divisors (1).

997961 is an equidigital number, since it uses as much as digits as its factorization.

997961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30618, while the sum is 41.

The square root of 997961 is about 998.9799797794. The cubic root of 997961 is about 99.9319870863.

The spelling of 997961 in words is "nine hundred ninety-seven thousand, nine hundred sixty-one".