256297247 has 2 divisors, whose sum is σ = 256297248. Its totient is φ = 256297246.

The previous prime is 256297231. The next prime is 256297309. The reversal of 256297247 is 742792652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256297247 - 2⁴ = 256297231 is a prime.

It is a super-3 number, since 3×256297247³ (a number of 26 digits) contains 333 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 256297198 and 256297207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256297747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128148623 + 128148624.

It is an arithmetic number, because the mean of its divisors is an integer number (128148624).

Almost surely, 2^256297247 is an apocalyptic number.

256297247 is a deficient number, since it is larger than the sum of its proper divisors (1).

256297247 is an equidigital number, since it uses as much as digits as its factorization.

256297247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 423360, while the sum is 44.

The square root of 256297247 is about 16009.2862739099. The cubic root of 256297247 is about 635.2060810441.

The spelling of 256297247 in words is "two hundred fifty-six million, two hundred ninety-seven thousand, two hundred forty-seven".