991393303 has 2 divisors, whose sum is σ = 991393304. Its totient is φ = 991393302.

The previous prime is 991393297. The next prime is 991393367. The reversal of 991393303 is 303393199.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991393303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991393103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495696651 + 495696652.

It is an arithmetic number, because the mean of its divisors is an integer number (495696652).

Almost surely, 2^991393303 is an apocalyptic number.

991393303 is a deficient number, since it is larger than the sum of its proper divisors (1).

991393303 is an equidigital number, since it uses as much as digits as its factorization.

991393303 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 59049, while the sum is 40.

The square root of 991393303 is about 31486.3986984857. The cubic root of 991393303 is about 997.1228308368.

The spelling of 991393303 in words is "nine hundred ninety-one million, three hundred ninety-three thousand, three hundred three".