1256165 has 4 divisors (see below), whose sum is σ = 1507404. Its totient is φ = 1004928.

The previous prime is 1256161. The next prime is 1256197. The reversal of 1256165 is 5616521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5616521 = 1021 ⋅5501.

It can be written as a sum of positive squares in 2 ways, for example, as 538756 + 717409 = 734^2 + 847^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256165 - 2² = 1256161 is a prime.

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

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 (1256161) 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, 125612 + ... + 125621.

It is an arithmetic number, because the mean of its divisors is an integer number (376851).

2^1256165 is an apocalyptic number.

It is an amenable number.

1256165 is a deficient number, since it is larger than the sum of its proper divisors (251239).

1256165 is an equidigital number, since it uses as much as digits as its factorization.

1256165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251238.

The product of its digits is 1800, while the sum is 26.

The square root of 1256165 is about 1120.7876694539. The cubic root of 1256165 is about 107.8985386848.

The spelling of 1256165 in words is "one million, two hundred fifty-six thousand, one hundred sixty-five".