7989797721 has 8 divisors (see below), whose sum is σ = 10654226784. Its totient is φ = 5325950240.

The previous prime is 7989797719. The next prime is 7989797729. The reversal of 7989797721 is 1277979897.

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

It is a cyclic number.

It is not a de Polignac number, because 7989797721 - 2¹ = 7989797719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7989797729) 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, 112260 + ... + 169061.

It is an arithmetic number, because the mean of its divisors is an integer number (1331778348).

Almost surely, 2^7989797721 is an apocalyptic number.

It is an amenable number.

7989797721 is a deficient number, since it is larger than the sum of its proper divisors (2664429063).

7989797721 is a wasteful number, since it uses less digits than its factorization.

7989797721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290791.

The product of its digits is 28005264, while the sum is 66.

The square root of 7989797721 is about 89385.6684318018. The cubic root of 7989797721 is about 1999.1494484156.

The spelling of 7989797721 in words is "seven billion, nine hundred eighty-nine million, seven hundred ninety-seven thousand, seven hundred twenty-one".