2256161 has 4 divisors (see below), whose sum is σ = 2284800. Its totient is φ = 2227524.

The previous prime is 2256131. The next prime is 2256169. The reversal of 2256161 is 1616522.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1616522 = 2 ⋅808261.

It is a cyclic number.

It is not a de Polignac number, because 2256161 - 2⁶ = 2256097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2256169) 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, 14201 + ... + 14358.

It is an arithmetic number, because the mean of its divisors is an integer number (571200).

2^2256161 is an apocalyptic number.

It is an amenable number.

2256161 is a deficient number, since it is larger than the sum of its proper divisors (28639).

2256161 is an equidigital number, since it uses as much as digits as its factorization.

2256161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28638.

The product of its digits is 720, while the sum is 23.

The square root of 2256161 is about 1502.0522627392. The cubic root of 2256161 is about 131.1565635819.

It can be divided in two parts, 22561 and 61, that added together give a palindrome (22622).

The spelling of 2256161 in words is "two million, two hundred fifty-six thousand, one hundred sixty-one".