2257681 has 4 divisors (see below), whose sum is σ = 2264500. Its totient is φ = 2250864.

The previous prime is 2257667. The next prime is 2257687. The reversal of 2257681 is 1867522.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1867522 = 2 ⋅933761.

It can be written as a sum of positive squares in 2 ways, for example, as 781456 + 1476225 = 884^2 + 1215^2 .

It is a cyclic number.

It is not a de Polignac number, because 2257681 - 2⁵ = 2257649 is a prime.

It is a super-2 number, since 2×2257681² = 10194246995522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2257687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2886 + ... + 3583.

It is an arithmetic number, because the mean of its divisors is an integer number (566125).

2^2257681 is an apocalyptic number.

It is an amenable number.

2257681 is a deficient number, since it is larger than the sum of its proper divisors (6819).

2257681 is an equidigital number, since it uses as much as digits as its factorization.

2257681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6818.

The product of its digits is 6720, while the sum is 31.

The square root of 2257681 is about 1502.5581519529. The cubic root of 2257681 is about 131.1860108337.

The spelling of 2257681 in words is "two million, two hundred fifty-seven thousand, six hundred eighty-one".