991883 has 2 divisors, whose sum is σ = 991884. Its totient is φ = 991882.

The previous prime is 991873. The next prime is 991889. The reversal of 991883 is 388199.

991883 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 is a cyclic number.

It is not a de Polignac number, because 991883 - 2⁴ = 991867 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991883.

It is not a weakly prime, because it can be changed into another prime (991889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495941 + 495942.

It is an arithmetic number, because the mean of its divisors is an integer number (495942).

2⁹⁹¹⁸⁸³ is an apocalyptic number.

991883 is a deficient number, since it is larger than the sum of its proper divisors (1).

991883 is an equidigital number, since it uses as much as digits as its factorization.

991883 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 38.

The square root of 991883 is about 995.9332306937. The cubic root of 991883 is about 99.7286979510.

It can be divided in two parts, 9918 and 83, that added together give a palindrome (10001).

The spelling of 991883 in words is "nine hundred ninety-one thousand, eight hundred eighty-three".