256665503 has 2 divisors, whose sum is σ = 256665504. Its totient is φ = 256665502.

The previous prime is 256665481. The next prime is 256665551. The reversal of 256665503 is 305566652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256665503 - 2¹⁰ = 256664479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256665553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128332751 + 128332752.

It is an arithmetic number, because the mean of its divisors is an integer number (128332752).

Almost surely, 2^256665503 is an apocalyptic number.

256665503 is a deficient number, since it is larger than the sum of its proper divisors (1).

256665503 is an equidigital number, since it uses as much as digits as its factorization.

256665503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162000, while the sum is 38.

The square root of 256665503 is about 16020.7834702302. The cubic root of 256665503 is about 635.5101635224.

The spelling of 256665503 in words is "two hundred fifty-six million, six hundred sixty-five thousand, five hundred three".