2256570821 has 4 divisors (see below), whose sum is σ = 2257045644. Its totient is φ = 2256096000.

The previous prime is 2256570709. The next prime is 2256570847. The reversal of 2256570821 is 1280756522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1062108100 + 1194462721 = 32590^2 + 34561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2256570821 is a prime.

It is a super-2 number, since 2×2256570821² = 10184223740377228082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2256570521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230210 + ... + 239811.

It is an arithmetic number, because the mean of its divisors is an integer number (564261411).

Almost surely, 2^2256570821 is an apocalyptic number.

It is an amenable number.

2256570821 is a deficient number, since it is larger than the sum of its proper divisors (474823).

2256570821 is an equidigital number, since it uses as much as digits as its factorization.

2256570821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474822.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 2256570821 is about 47503.3769431185. The cubic root of 2256570821 is about 1311.6450442472.

The spelling of 2256570821 in words is "two billion, two hundred fifty-six million, five hundred seventy thousand, eight hundred twenty-one".