28315411781 has 4 divisors (see below), whose sum is σ = 28350413100. Its totient is φ = 28280410464.

The previous prime is 28315411723. The next prime is 28315411783. The reversal of 28315411781 is 18711451382.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19386106756 + 8929305025 = 139234^2 + 94495^2 .

It is a cyclic number.

It is not a de Polignac number, because 28315411781 - 2¹⁴ = 28315395397 is a prime.

It is a super-2 number, since 2×28315411781² (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 (28315411783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17499446 + ... + 17501063.

It is an arithmetic number, because the mean of its divisors is an integer number (7087603275).

Almost surely, 2^28315411781 is an apocalyptic number.

It is an amenable number.

28315411781 is a deficient number, since it is larger than the sum of its proper divisors (35001319).

28315411781 is an equidigital number, since it uses as much as digits as its factorization.

28315411781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35001318.

The product of its digits is 53760, while the sum is 41.

The spelling of 28315411781 in words is "twenty-eight billion, three hundred fifteen million, four hundred eleven thousand, seven hundred eighty-one".