256161305728651 has 2 divisors, whose sum is σ = 256161305728652. Its totient is φ = 256161305728650.

The previous prime is 256161305728639. The next prime is 256161305728709. The reversal of 256161305728651 is 156827503161652.

256161305728651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (256161305728709) can be obtained adding 256161305728651 to its sum of digits (58).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256161305728651 - 2²⁹ = 256160768857739 is a prime.

It is a super-2 number, since 2×256161305728651² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256161305738651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128080652864325 + 128080652864326.

It is an arithmetic number, because the mean of its divisors is an integer number (128080652864326).

Almost surely, 2^{256161305728651} is an apocalyptic number.

256161305728651 is a deficient number, since it is larger than the sum of its proper divisors (1).

256161305728651 is an equidigital number, since it uses as much as digits as its factorization.

256161305728651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144000, while the sum is 58.

The spelling of 256161305728651 in words is "two hundred fifty-six trillion, one hundred sixty-one billion, three hundred five million, seven hundred twenty-eight thousand, six hundred fifty-one".