28871105521 has 2 divisors, whose sum is σ = 28871105522. Its totient is φ = 28871105520.

The previous prime is 28871105509. The next prime is 28871105531. The reversal of 28871105521 is 12550117882.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21915545521 + 6955560000 = 148039^2 + 83400^2 .

It is a cyclic number.

It is not a de Polignac number, because 28871105521 - 2²¹ = 28869008369 is a prime.

It is not a weakly prime, because it can be changed into another prime (28871105531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14435552760 + 14435552761.

It is an arithmetic number, because the mean of its divisors is an integer number (14435552761).

Almost surely, 2^28871105521 is an apocalyptic number.

It is an amenable number.

28871105521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28871105521 is an equidigital number, since it uses as much as digits as its factorization.

28871105521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 44800, while the sum is 40.

The spelling of 28871105521 in words is "twenty-eight billion, eight hundred seventy-one million, one hundred five thousand, five hundred twenty-one".