2191337591 has 4 divisors (see below), whose sum is σ = 2192847192. Its totient is φ = 2189827992.

The previous prime is 2191337569. The next prime is 2191337593. The reversal of 2191337591 is 1957331912.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2191337591 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 (2191337593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 752621 + ... + 755526.

It is an arithmetic number, because the mean of its divisors is an integer number (548211798).

Almost surely, 2^2191337591 is an apocalyptic number.

2191337591 is a deficient number, since it is larger than the sum of its proper divisors (1509601).

2191337591 is a wasteful number, since it uses less digits than its factorization.

2191337591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509600.

The product of its digits is 51030, while the sum is 41.

The square root of 2191337591 is about 46811.7249308333. The cubic root of 2191337591 is about 1298.8821931711.

The spelling of 2191337591 in words is "two billion, one hundred ninety-one million, three hundred thirty-seven thousand, five hundred ninety-one".