791221 has 4 divisors (see below), whose sum is σ = 793612. Its totient is φ = 788832.

The previous prime is 791209. The next prime is 791227. The reversal of 791221 is 122197.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122197 = 89 ⋅1373.

It can be written as a sum of positive squares in 2 ways, for example, as 555025 + 236196 = 745^2 + 486^2 .

It is a cyclic number.

It is not a de Polignac number, because 791221 - 2⁷ = 791093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 791192 and 791201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (791227) 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, 600 + ... + 1393.

It is an arithmetic number, because the mean of its divisors is an integer number (198403).

2⁷⁹¹²²¹ is an apocalyptic number.

It is an amenable number.

791221 is a deficient number, since it is larger than the sum of its proper divisors (2391).

791221 is a wasteful number, since it uses less digits than its factorization.

791221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2390.

The product of its digits is 252, while the sum is 22.

The square root of 791221 is about 889.5060427001. The cubic root of 791221 is about 92.4909560186.

The spelling of 791221 in words is "seven hundred ninety-one thousand, two hundred twenty-one".