1256161 has 2 divisors, whose sum is σ = 1256162. Its totient is φ = 1256160.

The previous prime is 1256149. The next prime is 1256197. The reversal of 1256161 is 1616521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 913936 + 342225 = 956^2 + 585^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256161 - 2¹³ = 1247969 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (1251161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628080 + 628081.

It is an arithmetic number, because the mean of its divisors is an integer number (628081).

2^1256161 is an apocalyptic number.

It is an amenable number.

1256161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256161 is an equidigital number, since it uses as much as digits as its factorization.

1256161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 22.

The square root of 1256161 is about 1120.7858849932. The cubic root of 1256161 is about 107.8984241578.

Adding to 1256161 its product of digits (360), we get a palindrome (1256521).

The spelling of 1256161 in words is "one million, two hundred fifty-six thousand, one hundred sixty-one".