28673763681 has 4 divisors (see below), whose sum is σ = 38231684912. Its totient is φ = 19115842452.

The previous prime is 28673763637. The next prime is 28673763691. The reversal of 28673763681 is 18636737682.

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.

It is not a de Polignac number, because 28673763681 - 2⁹ = 28673763169 is a prime.

It is a super-2 number, since 2×28673763681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28673763611) 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, 4778960611 + ... + 4778960616.

It is an arithmetic number, because the mean of its divisors is an integer number (9557921228).

Almost surely, 2^28673763681 is an apocalyptic number.

It is an amenable number.

28673763681 is a deficient number, since it is larger than the sum of its proper divisors (9557921231).

28673763681 is an equidigital number, since it uses as much as digits as its factorization.

28673763681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9557921230.

The product of its digits is 12192768, while the sum is 57.

The spelling of 28673763681 in words is "twenty-eight billion, six hundred seventy-three million, seven hundred sixty-three thousand, six hundred eighty-one".