28728386649 has 24 divisors (see below), whose sum is σ = 44027867520. Its totient is φ = 17988594048.

The previous prime is 28728386623. The next prime is 28728386651. The reversal of 28728386649 is 94668382782.

It is a de Polignac number, because none of the positive numbers 2^k-28728386649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28728385649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118269 + ... + 267290.

It is an arithmetic number, because the mean of its divisors is an integer number (1834494480).

Almost surely, 2^28728386649 is an apocalyptic number.

It is an amenable number.

28728386649 is a deficient number, since it is larger than the sum of its proper divisors (15299480871).

28728386649 is a wasteful number, since it uses less digits than its factorization.

28728386649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386069 (or 386066 counting only the distinct ones).

The product of its digits is 55738368, while the sum is 63.

The spelling of 28728386649 in words is "twenty-eight billion, seven hundred twenty-eight million, three hundred eighty-six thousand, six hundred forty-nine".