28529581 has 2 divisors, whose sum is σ = 28529582. Its totient is φ = 28529580.

The previous prime is 28529561. The next prime is 28529617. The reversal of 28529581 is 18592582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16564900 + 11964681 = 4070^2 + 3459^2 .

It is a cyclic number.

It is not a de Polignac number, because 28529581 - 2⁵ = 28529549 is a prime.

It is a super-2 number, since 2×28529581² = 1627873984071122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28529531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14264790 + 14264791.

It is an arithmetic number, because the mean of its divisors is an integer number (14264791).

Almost surely, 2^28529581 is an apocalyptic number.

It is an amenable number.

28529581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28529581 is an equidigital number, since it uses as much as digits as its factorization.

28529581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57600, while the sum is 40.

The square root of 28529581 is about 5341.3089219778. The cubic root of 28529581 is about 305.5613812125.

The spelling of 28529581 in words is "twenty-eight million, five hundred twenty-nine thousand, five hundred eighty-one".