28256686636 has 6 divisors (see below), whose sum is σ = 49449201620. Its totient is φ = 14128343316.

The previous prime is 28256686553. The next prime is 28256686637. The reversal of 28256686636 is 63668665282.

It is not an unprimeable number, because it can be changed into a prime (28256686637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3532085826 + ... + 3532085833.

Almost surely, 2^28256686636 is an apocalyptic number.

It is an amenable number.

28256686636 is a deficient number, since it is larger than the sum of its proper divisors (21192514984).

28256686636 is a wasteful number, since it uses less digits than its factorization.

28256686636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7064171663 (or 7064171661 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 58.

The spelling of 28256686636 in words is "twenty-eight billion, two hundred fifty-six million, six hundred eighty-six thousand, six hundred thirty-six".