28133334781 has 2 divisors, whose sum is σ = 28133334782. Its totient is φ = 28133334780.

The previous prime is 28133334703. The next prime is 28133334821. The reversal of 28133334781 is 18743333182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25806816025 + 2326518756 = 160645^2 + 48234^2 .

It is a cyclic number.

It is not a de Polignac number, because 28133334781 - 2⁹ = 28133334269 is a prime.

It is a super-2 number, since 2×28133334781² (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 (28133334881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14066667390 + 14066667391.

It is an arithmetic number, because the mean of its divisors is an integer number (14066667391).

Almost surely, 2^28133334781 is an apocalyptic number.

It is an amenable number.

28133334781 is a deficient number, since it is larger than the sum of its proper divisors (1).

28133334781 is an equidigital number, since it uses as much as digits as its factorization.

28133334781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 43.

The spelling of 28133334781 in words is "twenty-eight billion, one hundred thirty-three million, three hundred thirty-four thousand, seven hundred eighty-one".