28555719581 has 2 divisors, whose sum is σ = 28555719582. Its totient is φ = 28555719580.

The previous prime is 28555719551. The next prime is 28555719607. The reversal of 28555719581 is 18591755582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18315291556 + 10240428025 = 135334^2 + 101195^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28555719581 is a prime.

It is a super-2 number, since 2×28555719581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28555719541) 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, 14277859790 + 14277859791.

It is an arithmetic number, because the mean of its divisors is an integer number (14277859791).

Almost surely, 2^28555719581 is an apocalyptic number.

It is an amenable number.

28555719581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28555719581 is an equidigital number, since it uses as much as digits as its factorization.

28555719581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040000, while the sum is 56.

The spelling of 28555719581 in words is "twenty-eight billion, five hundred fifty-five million, seven hundred nineteen thousand, five hundred eighty-one".