727991 has 12 divisors (see below), whose sum is σ = 847320. Its totient is φ = 620160.

The previous prime is 727981. The next prime is 727997. The reversal of 727991 is 199727.

It is a de Polignac number, because none of the positive numbers 2^k-727991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (727997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3065 + ... + 3293.

It is an arithmetic number, because the mean of its divisors is an integer number (70610).

2⁷²⁷⁹⁹¹ is an apocalyptic number.

727991 is a deficient number, since it is larger than the sum of its proper divisors (119329).

727991 is a wasteful number, since it uses less digits than its factorization.

727991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 257 counting only the distinct ones).

The product of its digits is 7938, while the sum is 35.

The square root of 727991 is about 853.2238862104. The cubic root of 727991 is about 89.9584581945.

The spelling of 727991 in words is "seven hundred twenty-seven thousand, nine hundred ninety-one".