2191238805 has 16 divisors (see below), whose sum is σ = 4006836864. Its totient is φ = 1001709120.

The previous prime is 2191238801. The next prime is 2191238807. The reversal of 2191238805 is 5088321912.

It is not a de Polignac number, because 2191238805 - 2² = 2191238801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191238801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10434366 + ... + 10434575.

It is an arithmetic number, because the mean of its divisors is an integer number (250427304).

Almost surely, 2^2191238805 is an apocalyptic number.

It is an amenable number.

2191238805 is a deficient number, since it is larger than the sum of its proper divisors (1815598059).

2191238805 is a wasteful number, since it uses less digits than its factorization.

2191238805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20868956.

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 2191238805 is about 46810.6697773061. The cubic root of 2191238805 is about 1298.8626749090.

The spelling of 2191238805 in words is "two billion, one hundred ninety-one million, two hundred thirty-eight thousand, eight hundred five".