25928728561 has 2 divisors, whose sum is σ = 25928728562. Its totient is φ = 25928728560.

The previous prime is 25928728547. The next prime is 25928728577. The reversal of 25928728561 is 16582782952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16968970225 + 8959758336 = 130265^2 + 94656^2 .

It is a cyclic number.

It is not a de Polignac number, because 25928728561 - 2¹³ = 25928720369 is a prime.

It is not a weakly prime, because it can be changed into another prime (25928728531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12964364280 + 12964364281.

It is an arithmetic number, because the mean of its divisors is an integer number (12964364281).

Almost surely, 2^25928728561 is an apocalyptic number.

It is an amenable number.

25928728561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25928728561 is an equidigital number, since it uses as much as digits as its factorization.

25928728561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4838400, while the sum is 55.

The spelling of 25928728561 in words is "twenty-five billion, nine hundred twenty-eight million, seven hundred twenty-eight thousand, five hundred sixty-one".