2256781221 has 48 divisors (see below), whose sum is σ = 3505582080. Its totient is φ = 1394820000.

The previous prime is 2256781213. The next prime is 2256781243. The reversal of 2256781221 is 1221876522.

It is a happy number.

It is not a de Polignac number, because 2256781221 - 2³ = 2256781213 is a prime.

It is a super-2 number, since 2×2256781221² = 10186122958916501682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2256781291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1832676 + ... + 1833906.

It is an arithmetic number, because the mean of its divisors is an integer number (73032960).

Almost surely, 2^2256781221 is an apocalyptic number.

It is an amenable number.

2256781221 is a deficient number, since it is larger than the sum of its proper divisors (1248800859).

2256781221 is a wasteful number, since it uses less digits than its factorization.

2256781221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478 (or 1475 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 2256781221 is about 47505.5914708995. The cubic root of 2256781221 is about 1311.6858083922.

The spelling of 2256781221 in words is "two billion, two hundred fifty-six million, seven hundred eighty-one thousand, two hundred twenty-one".