28531145658881 has 2 divisors, whose sum is σ = 28531145658882. Its totient is φ = 28531145658880.

The previous prime is 28531145658859. The next prime is 28531145658989. The reversal of 28531145658881 is 18885654113582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17589770208256 + 10941375450625 = 4194016^2 + 3307775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28531145658881 is a prime.

It is a super-2 number, since 2×28531145658881² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28531145648881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14265572829440 + 14265572829441.

It is an arithmetic number, because the mean of its divisors is an integer number (14265572829441).

Almost surely, 2^{28531145658881} is an apocalyptic number.

It is an amenable number.

28531145658881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28531145658881 is an equidigital number, since it uses as much as digits as its factorization.

28531145658881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 73728000, while the sum is 65.

The spelling of 28531145658881 in words is "twenty-eight trillion, five hundred thirty-one billion, one hundred forty-five million, six hundred fifty-eight thousand, eight hundred eighty-one".