2191506895 has 4 divisors (see below), whose sum is σ = 2629808280. Its totient is φ = 1753205512.

The previous prime is 2191506893. The next prime is 2191506899. The reversal of 2191506895 is 5986051912.

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 2191506895 - 2¹ = 2191506893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191506893) 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, 219150685 + ... + 219150694.

It is an arithmetic number, because the mean of its divisors is an integer number (657452070).

Almost surely, 2^2191506895 is an apocalyptic number.

2191506895 is a deficient number, since it is larger than the sum of its proper divisors (438301385).

2191506895 is an equidigital number, since it uses as much as digits as its factorization.

2191506895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438301384.

The product of its (nonzero) digits is 194400, while the sum is 46.

The square root of 2191506895 is about 46813.5332462740. The cubic root of 2191506895 is about 1298.9156431042.

The spelling of 2191506895 in words is "two billion, one hundred ninety-one million, five hundred six thousand, eight hundred ninety-five".