28581229 has 2 divisors, whose sum is σ = 28581230. Its totient is φ = 28581228.

The previous prime is 28581209. The next prime is 28581239. The reversal of 28581229 is 92218582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23785129 + 4796100 = 4877^2 + 2190^2 .

It is a cyclic number.

It is not a de Polignac number, because 28581229 - 2¹³ = 28573037 is a prime.

It is a super-3 number, since 3×28581229³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28581209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14290614 + 14290615.

It is an arithmetic number, because the mean of its divisors is an integer number (14290615).

Almost surely, 2^28581229 is an apocalyptic number.

It is an amenable number.

28581229 is a deficient number, since it is larger than the sum of its proper divisors (1).

28581229 is an equidigital number, since it uses as much as digits as its factorization.

28581229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 37.

The square root of 28581229 is about 5346.1415057965. The cubic root of 28581229 is about 305.7456591899.

The spelling of 28581229 in words is "twenty-eight million, five hundred eighty-one thousand, two hundred twenty-nine".