28320787685 has 32 divisors (see below), whose sum is σ = 35833674240. Its totient is φ = 21445946368.

The previous prime is 28320787661. The next prime is 28320787721. The reversal of 28320787685 is 58678702382.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28320787685 - 2¹⁴ = 28320771301 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28320787685.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4471601 + ... + 4477929.

It is an arithmetic number, because the mean of its divisors is an integer number (1119802320).

Almost surely, 2^28320787685 is an apocalyptic number.

It is an amenable number.

28320787685 is a deficient number, since it is larger than the sum of its proper divisors (7512886555).

28320787685 is a wasteful number, since it uses less digits than its factorization.

28320787685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6757.

The product of its (nonzero) digits is 9031680, while the sum is 56.

The spelling of 28320787685 in words is "twenty-eight billion, three hundred twenty million, seven hundred eighty-seven thousand, six hundred eighty-five".