79748640721 has 8 divisors (see below), whose sum is σ = 84447995904. Its totient is φ = 75050203200.

The previous prime is 79748640691. The next prime is 79748640793. The reversal of 79748640721 is 12704684797.

It is a happy number.

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 79748640721 - 2⁷ = 79748640593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79748640221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46305 + ... + 402046.

It is an arithmetic number, because the mean of its divisors is an integer number (10555999488).

Almost surely, 2^79748640721 is an apocalyptic number.

It is an amenable number.

79748640721 is a deficient number, since it is larger than the sum of its proper divisors (4699355183).

79748640721 is a wasteful number, since it uses less digits than its factorization.

79748640721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458831.

The product of its (nonzero) digits is 4741632, while the sum is 55.

The spelling of 79748640721 in words is "seventy-nine billion, seven hundred forty-eight million, six hundred forty thousand, seven hundred twenty-one".