256816867357 has 2 divisors, whose sum is σ = 256816867358. Its totient is φ = 256816867356.

The previous prime is 256816867339. The next prime is 256816867369. The reversal of 256816867357 is 753768618652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221948400996 + 34868466361 = 471114^2 + 186731^2 .

It is a cyclic number.

It is not a de Polignac number, because 256816867357 - 2¹¹ = 256816865309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256816867327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128408433678 + 128408433679.

It is an arithmetic number, because the mean of its divisors is an integer number (128408433679).

Almost surely, 2^256816867357 is an apocalyptic number.

It is an amenable number.

256816867357 is a deficient number, since it is larger than the sum of its proper divisors (1).

256816867357 is an equidigital number, since it uses as much as digits as its factorization.

256816867357 is an evil number, because the sum of its binary digits is even.

The product of its digits is 101606400, while the sum is 64.

The spelling of 256816867357 in words is "two hundred fifty-six billion, eight hundred sixteen million, eight hundred sixty-seven thousand, three hundred fifty-seven".