2731221 has 6 divisors (see below), whose sum is σ = 3945110. Its totient is φ = 1820808.

The previous prime is 2731207. The next prime is 2731241. The reversal of 2731221 is 1221372.

It can be written as a sum of positive squares in only one way, i.e., 1703025 + 1028196 = 1305^2 + 1014^2 .

It is not a de Polignac number, because 2731221 - 2⁵ = 2731189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2731194 and 2731203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2731241) 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, 151726 + ... + 151743.

2^2731221 is an apocalyptic number.

It is an amenable number.

2731221 is a deficient number, since it is larger than the sum of its proper divisors (1213889).

2731221 is a wasteful number, since it uses less digits than its factorization.

2731221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303475 (or 303472 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 2731221 is about 1652.6406142897. The cubic root of 2731221 is about 139.7823318189.

Adding to 2731221 its reverse (1221372), we get a palindrome (3952593).

It can be divided in two parts, 273 and 1221, that multiplied together give a palindrome (333333).

The spelling of 2731221 in words is "two million, seven hundred thirty-one thousand, two hundred twenty-one".