256205261 has 8 divisors (see below), whose sum is σ = 276736824. Its totient is φ = 235791360.

The previous prime is 256205219. The next prime is 256205267. The reversal of 256205261 is 162502652.

It can be written as a sum of positive squares in 4 ways, for example, as 36602500 + 219602761 = 6050^2 + 14819^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256205261 - 2⁶ = 256205197 is a prime.

It is a super-2 number, since 2×256205261² = 131282271528156242, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256205267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24860 + ... + 33621.

It is an arithmetic number, because the mean of its divisors is an integer number (34592103).

Almost surely, 2^256205261 is an apocalyptic number.

It is an amenable number.

256205261 is a deficient number, since it is larger than the sum of its proper divisors (20531563).

256205261 is a wasteful number, since it uses less digits than its factorization.

256205261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58831.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 256205261 is about 16006.4131209962. The cubic root of 256205261 is about 635.1300793717.

The spelling of 256205261 in words is "two hundred fifty-six million, two hundred five thousand, two hundred sixty-one".