12775221 has 6 divisors (see below), whose sum is σ = 18453110. Its totient is φ = 8516808.

The previous prime is 12775207. The next prime is 12775229. The reversal of 12775221 is 12257721.

It can be written as a sum of positive squares in only one way, i.e., 9922500 + 2852721 = 3150^2 + 1689^2 .

It is not a de Polignac number, because 12775221 - 2⁹ = 12774709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12775229) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 709726 + ... + 709743.

Almost surely, 2^12775221 is an apocalyptic number.

It is an amenable number.

12775221 is a deficient number, since it is larger than the sum of its proper divisors (5677889).

12775221 is a wasteful number, since it uses less digits than its factorization.

12775221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419475 (or 1419472 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 12775221 is about 3574.2441158936. The cubic root of 12775221 is about 233.7703752245.

It can be divided in two parts, 12775 and 221, that added together give a square (12996 = 114²).

The spelling of 12775221 in words is "twelve million, seven hundred seventy-five thousand, two hundred twenty-one".