799663721 has 8 divisors (see below), whose sum is σ = 821697864. Its totient is φ = 777651840.

The previous prime is 799663717. The next prime is 799663727. The reversal of 799663721 is 127366997.

It can be written as a sum of positive squares in 4 ways, for example, as 18181696 + 781482025 = 4264^2 + 27955^2 .

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 799663721 - 2² = 799663717 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 799663721.

It is not an unprimeable number, because it can be changed into a prime (799663727) 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, 88991 + ... + 97563.

It is an arithmetic number, because the mean of its divisors is an integer number (102712233).

Almost surely, 2^799663721 is an apocalyptic number.

It is an amenable number.

799663721 is a deficient number, since it is larger than the sum of its proper divisors (22034143).

799663721 is a wasteful number, since it uses less digits than its factorization.

799663721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11131.

The product of its digits is 857304, while the sum is 50.

The square root of 799663721 is about 28278.3259935945. The cubic root of 799663721 is about 928.1876760888.

It can be divided in two parts, 7996 and 63721, that added together give a palindrome (71717).

The spelling of 799663721 in words is "seven hundred ninety-nine million, six hundred sixty-three thousand, seven hundred twenty-one".