28253521 has 2 divisors, whose sum is σ = 28253522. Its totient is φ = 28253520.

The previous prime is 28253501. The next prime is 28253549. The reversal of 28253521 is 12535282.

It is an a-pointer prime, because the next prime (28253549) can be obtained adding 28253521 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24601600 + 3651921 = 4960^2 + 1911^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28253521 is a prime.

It is a super-2 number, since 2×28253521² = 1596522897794882, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28253521.

It is not a weakly prime, because it can be changed into another prime (28253501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14126760 + 14126761.

It is an arithmetic number, because the mean of its divisors is an integer number (14126761).

Almost surely, 2^28253521 is an apocalyptic number.

It is an amenable number.

28253521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28253521 is an equidigital number, since it uses as much as digits as its factorization.

28253521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4800, while the sum is 28.

The square root of 28253521 is about 5315.4041238649. The cubic root of 28253521 is about 304.5726200843.

The spelling of 28253521 in words is "twenty-eight million, two hundred fifty-three thousand, five hundred twenty-one".