8191291225 has 12 divisors (see below), whose sum is σ = 10938524716. Its totient is φ = 6048953280.

The previous prime is 8191291219. The next prime is 8191291253. The reversal of 8191291225 is 5221921918.

It can be written as a sum of positive squares in 6 ways, for example, as 1693157904 + 6498133321 = 41148^2 + 80611^2 .

It is a de Polignac number, because none of the positive numbers 2^k-8191291225 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12601662 + ... + 12602311.

Almost surely, 2^8191291225 is an apocalyptic number.

It is an amenable number.

8191291225 is a deficient number, since it is larger than the sum of its proper divisors (2747233491).

8191291225 is a wasteful number, since it uses less digits than its factorization.

8191291225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25203996 (or 25203991 counting only the distinct ones).

The product of its digits is 25920, while the sum is 40.

The square root of 8191291225 is about 90505.7524414885. The cubic root of 8191291225 is about 2015.8155400989.

The spelling of 8191291225 in words is "eight billion, one hundred ninety-one million, two hundred ninety-one thousand, two hundred twenty-five".