7920743993721 has 96 divisors (see below), whose sum is σ = 12584796224000. Its totient is φ = 4771172450304.

The previous prime is 7920743993681. The next prime is 7920743993731. The reversal of 7920743993721 is 1273993470297.

7920743993721 is a `hidden beast` number, since 7 + 9 + 207 + 4 + 399 + 37 + 2 + 1 = 666.

It is not a de Polignac number, because 7920743993721 - 2⁹ = 7920743993209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7920743993731) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 987989505 + ... + 987997521.

Almost surely, 2^{7920743993721} is an apocalyptic number.

It is an amenable number.

7920743993721 is a deficient number, since it is larger than the sum of its proper divisors (4664052230279).

7920743993721 is a wasteful number, since it uses less digits than its factorization.

7920743993721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9023 (or 9020 counting only the distinct ones).

The product of its (nonzero) digits is 36006768, while the sum is 63.

The spelling of 7920743993721 in words is "seven trillion, nine hundred twenty billion, seven hundred forty-three million, nine hundred ninety-three thousand, seven hundred twenty-one".