28358636821 has 16 divisors (see below), whose sum is σ = 28983001024. Its totient is φ = 27741377664.

The previous prime is 28358636777. The next prime is 28358636849. The reversal of 28358636821 is 12863685382.

It is a cyclic number.

It is not a de Polignac number, because 28358636821 - 2⁷ = 28358636693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28358636851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6506575 + ... + 6510931.

It is an arithmetic number, because the mean of its divisors is an integer number (1811437564).

Almost surely, 2^28358636821 is an apocalyptic number.

It is an amenable number.

28358636821 is a deficient number, since it is larger than the sum of its proper divisors (624364203).

28358636821 is a wasteful number, since it uses less digits than its factorization.

28358636821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5140.

The product of its digits is 3317760, while the sum is 52.

The spelling of 28358636821 in words is "twenty-eight billion, three hundred fifty-eight million, six hundred thirty-six thousand, eight hundred twenty-one".