28315821865 has 8 divisors (see below), whose sum is σ = 34701943680. Its totient is φ = 22170685872.

The previous prime is 28315821839. The next prime is 28315821881. The reversal of 28315821865 is 56812851382.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28315821865 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 60246195 + ... + 60246664.

It is an arithmetic number, because the mean of its divisors is an integer number (4337742960).

Almost surely, 2^28315821865 is an apocalyptic number.

It is an amenable number.

28315821865 is a deficient number, since it is larger than the sum of its proper divisors (6386121815).

28315821865 is a wasteful number, since it uses less digits than its factorization.

28315821865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120492911.

The product of its digits is 921600, while the sum is 49.

The spelling of 28315821865 in words is "twenty-eight billion, three hundred fifteen million, eight hundred twenty-one thousand, eight hundred sixty-five".