7991849728 has 18 divisors (see below), whose sum is σ = 15952481804. Its totient is φ = 3995924736.

The previous prime is 7991849681. The next prime is 7991849737. The reversal of 7991849728 is 8279481997.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a self number, because there is not a number n which added to its sum of digits gives 7991849728.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15608826 + ... + 15609337.

Almost surely, 2^7991849728 is an apocalyptic number.

It is an amenable number.

7991849728 is a deficient number, since it is larger than the sum of its proper divisors (7960632076).

7991849728 is an equidigital number, since it uses as much as digits as its factorization.

7991849728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31218179 (or 31218165 counting only the distinct ones).

The product of its digits is 18289152, while the sum is 64.

The square root of 7991849728 is about 89397.1460842011. The cubic root of 7991849728 is about 1999.3205798870.

The spelling of 7991849728 in words is "seven billion, nine hundred ninety-one million, eight hundred forty-nine thousand, seven hundred twenty-eight".