256515943 has 2 divisors, whose sum is σ = 256515944. Its totient is φ = 256515942.

The previous prime is 256515937. The next prime is 256515983. The reversal of 256515943 is 349515652.

It is an a-pointer prime, because the next prime (256515983) can be obtained adding 256515943 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256515943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256515896 and 256515905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256515983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128257971 + 128257972.

It is an arithmetic number, because the mean of its divisors is an integer number (128257972).

Almost surely, 2^256515943 is an apocalyptic number.

256515943 is a deficient number, since it is larger than the sum of its proper divisors (1).

256515943 is an equidigital number, since it uses as much as digits as its factorization.

256515943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162000, while the sum is 40.

The square root of 256515943 is about 16016.1151032327. The cubic root of 256515943 is about 635.3867014465.

The spelling of 256515943 in words is "two hundred fifty-six million, five hundred fifteen thousand, nine hundred forty-three".