28578539021 has 2 divisors, whose sum is σ = 28578539022. Its totient is φ = 28578539020.

The previous prime is 28578539009. The next prime is 28578539083. The reversal of 28578539021 is 12093587582.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28550860900 + 27678121 = 168970^2 + 5261^2 .

It is a cyclic number.

It is not a de Polignac number, because 28578539021 - 2⁶ = 28578538957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28578539221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14289269510 + 14289269511.

It is an arithmetic number, because the mean of its divisors is an integer number (14289269511).

Almost surely, 2^28578539021 is an apocalyptic number.

It is an amenable number.

28578539021 is a deficient number, since it is larger than the sum of its proper divisors (1).

28578539021 is an equidigital number, since it uses as much as digits as its factorization.

28578539021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1209600, while the sum is 50.

The spelling of 28578539021 in words is "twenty-eight billion, five hundred seventy-eight million, five hundred thirty-nine thousand, twenty-one".