1091938391 has 8 divisors (see below), whose sum is σ = 1097320224. Its totient is φ = 1086566400.

The previous prime is 1091938343. The next prime is 1091938427. The reversal of 1091938391 is 1938391901.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1091938391 - 2¹⁸ = 1091676247 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 (1091938321) 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 7 ways as a sum of consecutive naturals, for example, 314135 + ... + 317591.

It is an arithmetic number, because the mean of its divisors is an integer number (137165028).

Almost surely, 2^1091938391 is an apocalyptic number.

1091938391 is a deficient number, since it is larger than the sum of its proper divisors (5381833).

1091938391 is a wasteful number, since it uses less digits than its factorization.

1091938391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4921.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 1091938391 is about 33044.4910839916. The cubic root of 1091938391 is about 1029.7521604970.

The spelling of 1091938391 in words is "one billion, ninety-one million, nine hundred thirty-eight thousand, three hundred ninety-one".