256261361 has 4 divisors (see below), whose sum is σ = 256654452. Its totient is φ = 255868272.

The previous prime is 256261339. The next prime is 256261363. The reversal of 256261361 is 163162652.

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 109851361 + 146410000 = 10481^2 + 12100^2 .

It is a cyclic number.

It is not a de Polignac number, because 256261361 - 2¹⁰ = 256260337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256261363) 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, 195566 + ... + 196871.

It is an arithmetic number, because the mean of its divisors is an integer number (64163613).

Almost surely, 2^256261361 is an apocalyptic number.

It is an amenable number.

256261361 is a deficient number, since it is larger than the sum of its proper divisors (393091).

256261361 is an equidigital number, since it uses as much as digits as its factorization.

256261361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393090.

The product of its digits is 12960, while the sum is 32.

The square root of 256261361 is about 16008.1654476708. The cubic root of 256261361 is about 635.1764330870.

The spelling of 256261361 in words is "two hundred fifty-six million, two hundred sixty-one thousand, three hundred sixty-one".