256187641 has 2 divisors, whose sum is σ = 256187642. Its totient is φ = 256187640.

The previous prime is 256187563. The next prime is 256187663. The reversal of 256187641 is 146781652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223652025 + 32535616 = 14955^2 + 5704^2 .

It is a cyclic number.

It is not a de Polignac number, because 256187641 - 2⁷ = 256187513 is a prime.

It is a super-2 number, since 2×256187641² = 131264214802289762, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 256187594 and 256187603.

It is not a weakly prime, because it can be changed into another prime (256187681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128093820 + 128093821.

It is an arithmetic number, because the mean of its divisors is an integer number (128093821).

Almost surely, 2^256187641 is an apocalyptic number.

It is an amenable number.

256187641 is a deficient number, since it is larger than the sum of its proper divisors (1).

256187641 is an equidigital number, since it uses as much as digits as its factorization.

256187641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 40.

The square root of 256187641 is about 16005.8627071458. The cubic root of 256187641 is about 635.1155191079.

The spelling of 256187641 in words is "two hundred fifty-six million, one hundred eighty-seven thousand, six hundred forty-one".