256507123265567 has 2 divisors, whose sum is σ = 256507123265568. Its totient is φ = 256507123265566.

The previous prime is 256507123265521. The next prime is 256507123265579. The reversal of 256507123265567 is 765562321705652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256507123265567 - 2¹² = 256507123261471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256507123268567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128253561632783 + 128253561632784.

It is an arithmetic number, because the mean of its divisors is an integer number (128253561632784).

Almost surely, 2^{256507123265567} is an apocalyptic number.

256507123265567 is a deficient number, since it is larger than the sum of its proper divisors (1).

256507123265567 is an equidigital number, since it uses as much as digits as its factorization.

256507123265567 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 158760000, while the sum is 62.

The spelling of 256507123265567 in words is "two hundred fifty-six trillion, five hundred seven billion, one hundred twenty-three million, two hundred sixty-five thousand, five hundred sixty-seven".