28493826821 has 2 divisors, whose sum is σ = 28493826822. Its totient is φ = 28493826820.

The previous prime is 28493826761. The next prime is 28493826833. The reversal of 28493826821 is 12862839482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28329602596 + 164224225 = 168314^2 + 12815^2 .

It is a cyclic number.

It is not a de Polignac number, because 28493826821 - 2³⁴ = 11313957637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28493826841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14246913410 + 14246913411.

It is an arithmetic number, because the mean of its divisors is an integer number (14246913411).

Almost surely, 2^28493826821 is an apocalyptic number.

It is an amenable number.

28493826821 is a deficient number, since it is larger than the sum of its proper divisors (1).

28493826821 is an equidigital number, since it uses as much as digits as its factorization.

28493826821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2654208, while the sum is 53.

The spelling of 28493826821 in words is "twenty-eight billion, four hundred ninety-three million, eight hundred twenty-six thousand, eight hundred twenty-one".