256402481 has 2 divisors, whose sum is σ = 256402482. Its totient is φ = 256402480.

The previous prime is 256402477. The next prime is 256402529. The reversal of 256402481 is 184204652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221533456 + 34869025 = 14884^2 + 5905^2 .

It is a cyclic number.

It is not a de Polignac number, because 256402481 - 2² = 256402477 is a prime.

It is a super-2 number, since 2×256402481² = 131484464525910722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256432481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128201240 + 128201241.

It is an arithmetic number, because the mean of its divisors is an integer number (128201241).

Almost surely, 2^256402481 is an apocalyptic number.

It is an amenable number.

256402481 is a deficient number, since it is larger than the sum of its proper divisors (1).

256402481 is an equidigital number, since it uses as much as digits as its factorization.

256402481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 256402481 is about 16012.5725915607. The cubic root of 256402481 is about 635.2930063244.

The spelling of 256402481 in words is "two hundred fifty-six million, four hundred two thousand, four hundred eighty-one".