7991268891 has 8 divisors (see below), whose sum is σ = 10655763264. Its totient is φ = 5327143560.

The previous prime is 7991268869. The next prime is 7991268899. The reversal of 7991268891 is 1988621997.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7991268891 - 2⁹ = 7991268379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7991268899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37005 + ... + 131726.

It is an arithmetic number, because the mean of its divisors is an integer number (1331970408).

Almost surely, 2^7991268891 is an apocalyptic number.

7991268891 is a deficient number, since it is larger than the sum of its proper divisors (2664494373).

7991268891 is a wasteful number, since it uses less digits than its factorization.

7991268891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184521.

The product of its digits is 3919104, while the sum is 60.

The square root of 7991268891 is about 89393.8973923836. The cubic root of 7991268891 is about 1999.2721427274.

The spelling of 7991268891 in words is "seven billion, nine hundred ninety-one million, two hundred sixty-eight thousand, eight hundred ninety-one".