28553521 has 2 divisors, whose sum is σ = 28553522. Its totient is φ = 28553520.

The previous prime is 28553513. The next prime is 28553549. The reversal of 28553521 is 12535582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16719921 + 11833600 = 4089^2 + 3440^2 .

It is a cyclic number.

It is not a de Polignac number, because 28553521 - 2³ = 28553513 is a prime.

It is a super-2 number, since 2×28553521² = 1630607122994882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28553501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14276760 + 14276761.

It is an arithmetic number, because the mean of its divisors is an integer number (14276761).

Almost surely, 2^28553521 is an apocalyptic number.

It is an amenable number.

28553521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28553521 is an equidigital number, since it uses as much as digits as its factorization.

28553521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12000, while the sum is 31.

The square root of 28553521 is about 5343.5494757698. The cubic root of 28553521 is about 305.6468257937.

The spelling of 28553521 in words is "twenty-eight million, five hundred fifty-three thousand, five hundred twenty-one".