1991327 has 6 divisors (see below), whose sum is σ = 2156472. Its totient is φ = 1837992.

The previous prime is 1991293. The next prime is 1991351. The reversal of 1991327 is 7231991.

It is a happy number.

It is not a de Polignac number, because 1991327 - 2⁸ = 1991071 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1991293 and 1991302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991357) 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 5 ways as a sum of consecutive naturals, for example, 5723 + ... + 6060.

It is an arithmetic number, because the mean of its divisors is an integer number (359412).

2^1991327 is an apocalyptic number.

1991327 is a deficient number, since it is larger than the sum of its proper divisors (165145).

1991327 is a wasteful number, since it uses less digits than its factorization.

1991327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11809 (or 11796 counting only the distinct ones).

The product of its digits is 3402, while the sum is 32.

The square root of 1991327 is about 1411.1438622621. The cubic root of 1991327 is about 125.8097195089.

The spelling of 1991327 in words is "one million, nine hundred ninety-one thousand, three hundred twenty-seven".