28686691139 has 4 divisors (see below), whose sum is σ = 28694701056. Its totient is φ = 28678681224.

The previous prime is 28686691129. The next prime is 28686691151. The reversal of 28686691139 is 93119668682.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28686691139 is a prime.

It is a super-2 number, since 2×28686691139² (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 (28686691129) 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, 3999584 + ... + 4006749.

It is an arithmetic number, because the mean of its divisors is an integer number (7173675264).

Almost surely, 2^28686691139 is an apocalyptic number.

28686691139 is a deficient number, since it is larger than the sum of its proper divisors (8009917).

28686691139 is an equidigital number, since it uses as much as digits as its factorization.

28686691139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8009916.

The product of its digits is 6718464, while the sum is 59.

The spelling of 28686691139 in words is "twenty-eight billion, six hundred eighty-six million, six hundred ninety-one thousand, one hundred thirty-nine".