2561221 has 8 divisors (see below), whose sum is σ = 2772224. Its totient is φ = 2352240.

The previous prime is 2561201. The next prime is 2561227. The reversal of 2561221 is 1221652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2561221 - 2⁷ = 2561093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3160 + ... + 3886.

It is an arithmetic number, because the mean of its divisors is an integer number (346528).

2^2561221 is an apocalyptic number.

It is an amenable number.

2561221 is a deficient number, since it is larger than the sum of its proper divisors (211003).

2561221 is a wasteful number, since it uses less digits than its factorization.

2561221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1011.

The product of its digits is 240, while the sum is 19.

The square root of 2561221 is about 1600.3815170140. The cubic root of 2561221 is about 136.8198210339.

Adding to 2561221 its reverse (1221652), we get a palindrome (3782873).

The spelling of 2561221 in words is "two million, five hundred sixty-one thousand, two hundred twenty-one".