798211721 has 4 divisors (see below), whose sum is σ = 798276612. Its totient is φ = 798146832.

The previous prime is 798211663. The next prime is 798211723. The reversal of 798211721 is 127112897.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 280194121 + 518017600 = 16739^2 + 22760^2 .

It is a cyclic number.

It is not a de Polignac number, because 798211721 - 2¹⁸ = 797949577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (798211723) 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, 7706 + ... + 40691.

It is an arithmetic number, because the mean of its divisors is an integer number (199569153).

Almost surely, 2^798211721 is an apocalyptic number.

It is an amenable number.

798211721 is a deficient number, since it is larger than the sum of its proper divisors (64891).

798211721 is a wasteful number, since it uses less digits than its factorization.

798211721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64890.

The product of its digits is 14112, while the sum is 38.

The square root of 798211721 is about 28252.6409562009. The cubic root of 798211721 is about 927.6255460280.

The spelling of 798211721 in words is "seven hundred ninety-eight million, two hundred eleven thousand, seven hundred twenty-one".