2556503221 has 4 divisors (see below), whose sum is σ = 2558332000. Its totient is φ = 2554674444.

The previous prime is 2556503141. The next prime is 2556503227. The reversal of 2556503221 is 1223056552.

It is a happy number.

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 2556503221 - 2²⁵ = 2522948789 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 (2556503227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 912291 + ... + 915088.

It is an arithmetic number, because the mean of its divisors is an integer number (639583000).

Almost surely, 2^2556503221 is an apocalyptic number.

It is an amenable number.

2556503221 is a deficient number, since it is larger than the sum of its proper divisors (1828779).

2556503221 is a wasteful number, since it uses less digits than its factorization.

2556503221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1828778.

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 2556503221 is about 50561.8751729008. The cubic root of 2556503221 is about 1367.3576185360.

Adding to 2556503221 its reverse (1223056552), we get a palindrome (3779559773).

The spelling of 2556503221 in words is "two billion, five hundred fifty-six million, five hundred three thousand, two hundred twenty-one".