775221 has 4 divisors (see below), whose sum is σ = 1033632. Its totient is φ = 516812.

The previous prime is 775193. The next prime is 775237. The reversal of 775221 is 122577.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 775221 - 2⁵ = 775189 is a prime.

It is a D-number.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 775191 and 775200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129201 + ... + 129206.

It is an arithmetic number, because the mean of its divisors is an integer number (258408).

2⁷⁷⁵²²¹ is an apocalyptic number.

It is an amenable number.

775221 is a deficient number, since it is larger than the sum of its proper divisors (258411).

775221 is a wasteful number, since it uses less digits than its factorization.

775221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258410.

The product of its digits is 980, while the sum is 24.

The square root of 775221 is about 880.4663537013. The cubic root of 775221 is about 91.8632577894.

Adding to 775221 its reverse (122577), we get a palindrome (897798).

The spelling of 775221 in words is "seven hundred seventy-five thousand, two hundred twenty-one".