799664861 has 4 divisors (see below), whose sum is σ = 819168924. Its totient is φ = 780160800.

The previous prime is 799664791. The next prime is 799664867. The reversal of 799664861 is 168466997.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 294808900 + 504855961 = 17170^2 + 22469^2 .

It is a cyclic number.

It is not a de Polignac number, because 799664861 - 2²⁶ = 732555997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 799664797 and 799664806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (799664867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9751970 + ... + 9752051.

It is an arithmetic number, because the mean of its divisors is an integer number (204792231).

Almost surely, 2^799664861 is an apocalyptic number.

It is an amenable number.

799664861 is a deficient number, since it is larger than the sum of its proper divisors (19504063).

799664861 is a wasteful number, since it uses less digits than its factorization.

799664861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19504062.

The product of its digits is 3919104, while the sum is 56.

The square root of 799664861 is about 28278.3461503674. The cubic root of 799664861 is about 928.1881171631.

The spelling of 799664861 in words is "seven hundred ninety-nine million, six hundred sixty-four thousand, eight hundred sixty-one".