2551221 has 12 divisors (see below), whose sum is σ = 3699072. Its totient is φ = 1694376.

The previous prime is 2551177. The next prime is 2551223. The reversal of 2551221 is 1221552.

It is a de Polignac number, because none of the positive numbers 2^k-2551221 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2551194 and 2551203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2551223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3900 + ... + 4506.

It is an arithmetic number, because the mean of its divisors is an integer number (308256).

2^2551221 is an apocalyptic number.

It is an amenable number.

2551221 is a deficient number, since it is larger than the sum of its proper divisors (1147851).

2551221 is a wasteful number, since it uses less digits than its factorization.

2551221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080 (or 1077 counting only the distinct ones).

The product of its digits is 200, while the sum is 18.

The square root of 2551221 is about 1597.2542064430. The cubic root of 2551221 is about 136.6415229043.

Adding to 2551221 its reverse (1221552), we get a palindrome (3772773).

It can be divided in two parts, 2551 and 221, that added together give a palindrome (2772).

The spelling of 2551221 in words is "two million, five hundred fifty-one thousand, two hundred twenty-one".