256653281 has 4 divisors (see below), whose sum is σ = 256703892. Its totient is φ = 256602672.

The previous prime is 256653259. The next prime is 256653289. The reversal of 256653281 is 182356652.

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 143017681 + 113635600 = 11959^2 + 10660^2 .

It is a cyclic number.

It is not a de Polignac number, because 256653281 - 2¹⁰ = 256652257 is a prime.

It is a super-2 number, since 2×256653281² = 131741813296129922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256653289) 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, 16730 + ... + 28163.

It is an arithmetic number, because the mean of its divisors is an integer number (64175973).

Almost surely, 2^256653281 is an apocalyptic number.

It is an amenable number.

256653281 is a deficient number, since it is larger than the sum of its proper divisors (50611).

256653281 is an equidigital number, since it uses as much as digits as its factorization.

256653281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50610.

The product of its digits is 86400, while the sum is 38.

The square root of 256653281 is about 16020.4020236697. The cubic root of 256653281 is about 635.5000760370.

The spelling of 256653281 in words is "two hundred fifty-six million, six hundred fifty-three thousand, two hundred eighty-one".