28060810781 has 4 divisors (see below), whose sum is σ = 28062045600. Its totient is φ = 28059575964.

The previous prime is 28060810721. The next prime is 28060810903. The reversal of 28060810781 is 18701806082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18701806082 = 2 ⋅9350903041.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28060810781 is a prime.

It is a super-2 number, since 2×28060810781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28060810711) 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 in 3 ways as a sum of consecutive naturals, for example, 582671 + ... + 628988.

It is an arithmetic number, because the mean of its divisors is an integer number (7015511400).

Almost surely, 2^28060810781 is an apocalyptic number.

It is an amenable number.

28060810781 is a deficient number, since it is larger than the sum of its proper divisors (1234819).

28060810781 is a wasteful number, since it uses less digits than its factorization.

28060810781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234818.

The product of its (nonzero) digits is 43008, while the sum is 41.

The spelling of 28060810781 in words is "twenty-eight billion, sixty million, eight hundred ten thousand, seven hundred eighty-one".