1991530327 has 4 divisors (see below), whose sum is σ = 2001639816. Its totient is φ = 1981420840.

The previous prime is 1991530319. The next prime is 1991530349. The reversal of 1991530327 is 7230351991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1991530327 - 2³ = 1991530319 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1991530327.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991530027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5054449 + ... + 5054842.

It is an arithmetic number, because the mean of its divisors is an integer number (500409954).

Almost surely, 2^1991530327 is an apocalyptic number.

1991530327 is a deficient number, since it is larger than the sum of its proper divisors (10109489).

1991530327 is a wasteful number, since it uses less digits than its factorization.

1991530327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10109488.

The product of its (nonzero) digits is 51030, while the sum is 40.

The square root of 1991530327 is about 44626.5652610640. The cubic root of 1991530327 is about 1258.1400135082.

The spelling of 1991530327 in words is "one billion, nine hundred ninety-one million, five hundred thirty thousand, three hundred twenty-seven".