2191543697 has 4 divisors (see below), whose sum is σ = 2504621376. Its totient is φ = 1878466020.

The previous prime is 2191543691. The next prime is 2191543747. The reversal of 2191543697 is 7963451912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2191543697 - 2³⁰ = 1117801873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2191543691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156538829 + ... + 156538842.

It is an arithmetic number, because the mean of its divisors is an integer number (626155344).

Almost surely, 2^2191543697 is an apocalyptic number.

It is an amenable number.

2191543697 is a deficient number, since it is larger than the sum of its proper divisors (313077679).

2191543697 is an equidigital number, since it uses as much as digits as its factorization.

2191543697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313077678.

The product of its digits is 408240, while the sum is 47.

The square root of 2191543697 is about 46813.9263147196. The cubic root of 2191543697 is about 1298.9229139652.

The spelling of 2191543697 in words is "two billion, one hundred ninety-one million, five hundred forty-three thousand, six hundred ninety-seven".