997959191 has 2 divisors, whose sum is σ = 997959192. Its totient is φ = 997959190.

The previous prime is 997959181. The next prime is 997959241. The reversal of 997959191 is 191959799.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 997959191 - 2¹⁰ = 997958167 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 997959191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997959181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498979595 + 498979596.

It is an arithmetic number, because the mean of its divisors is an integer number (498979596).

Almost surely, 2^997959191 is an apocalyptic number.

997959191 is a deficient number, since it is larger than the sum of its proper divisors (1).

997959191 is an equidigital number, since it uses as much as digits as its factorization.

997959191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2066715, while the sum is 59.

The square root of 997959191 is about 31590.4920980981. The cubic root of 997959191 is about 999.3192670411.

The spelling of 997959191 in words is "nine hundred ninety-seven million, nine hundred fifty-nine thousand, one hundred ninety-one".