991367983 has 2 divisors, whose sum is σ = 991367984. Its totient is φ = 991367982.

The previous prime is 991367977. The next prime is 991368013. The reversal of 991367983 is 389763199.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 991367983 - 2⁹ = 991367471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991367933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495683991 + 495683992.

It is an arithmetic number, because the mean of its divisors is an integer number (495683992).

Almost surely, 2^991367983 is an apocalyptic number.

991367983 is a deficient number, since it is larger than the sum of its proper divisors (1).

991367983 is an equidigital number, since it uses as much as digits as its factorization.

991367983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2204496, while the sum is 55.

The square root of 991367983 is about 31485.9966175441. The cubic root of 991367983 is about 997.1143419875.

The spelling of 991367983 in words is "nine hundred ninety-one million, three hundred sixty-seven thousand, nine hundred eighty-three".