28761761521 has 2 divisors, whose sum is σ = 28761761522. Its totient is φ = 28761761520.

The previous prime is 28761761477. The next prime is 28761761573. The reversal of 28761761521 is 12516716782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18214471521 + 10547290000 = 134961^2 + 102700^2 .

It is a cyclic number.

It is not a de Polignac number, because 28761761521 - 2¹⁹ = 28761237233 is a prime.

It is not a weakly prime, because it can be changed into another prime (28761767521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14380880760 + 14380880761.

It is an arithmetic number, because the mean of its divisors is an integer number (14380880761).

Almost surely, 2^28761761521 is an apocalyptic number.

It is an amenable number.

28761761521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28761761521 is an equidigital number, since it uses as much as digits as its factorization.

28761761521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 46.

The spelling of 28761761521 in words is "twenty-eight billion, seven hundred sixty-one million, seven hundred sixty-one thousand, five hundred twenty-one".