2191564263 has 64 divisors (see below), whose sum is σ = 3496919040. Its totient is φ = 1195171200.

The previous prime is 2191564237. The next prime is 2191564283. The reversal of 2191564263 is 3624651912.

It is not a de Polignac number, because 2191564263 - 2⁸ = 2191564007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191564283) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8086818 + ... + 8087088.

It is an arithmetic number, because the mean of its divisors is an integer number (54639360).

Almost surely, 2^2191564263 is an apocalyptic number.

2191564263 is a deficient number, since it is larger than the sum of its proper divisors (1305354777).

2191564263 is a wasteful number, since it uses less digits than its factorization.

2191564263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508.

The product of its digits is 77760, while the sum is 39.

The square root of 2191564263 is about 46814.1459710631. The cubic root of 2191564263 is about 1298.9269770928.

The spelling of 2191564263 in words is "two billion, one hundred ninety-one million, five hundred sixty-four thousand, two hundred sixty-three".