7191980721 has 12 divisors (see below), whose sum is σ = 10389278848. Its totient is φ = 4794255864.

The previous prime is 7191980717. The next prime is 7191980737. The reversal of 7191980721 is 1270891917.

It is a happy number.

7191980721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7191980721 - 2² = 7191980717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7191980021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117156 + ... + 167658.

Almost surely, 2^7191980721 is an apocalyptic number.

It is an amenable number.

7191980721 is a deficient number, since it is larger than the sum of its proper divisors (3197298127).

7191980721 is a wasteful number, since it uses less digits than its factorization.

7191980721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66332 (or 66329 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 45.

The square root of 7191980721 is about 84805.5465226184. The cubic root of 7191980721 is about 1930.2616020779.

The spelling of 7191980721 in words is "seven billion, one hundred ninety-one million, nine hundred eighty thousand, seven hundred twenty-one".