28582381 has 2 divisors, whose sum is σ = 28582382. Its totient is φ = 28582380.

The previous prime is 28582339. The next prime is 28582387. The reversal of 28582381 is 18328582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28185481 + 396900 = 5309^2 + 630^2 .

It is a cyclic number.

It is not a de Polignac number, because 28582381 - 2¹¹ = 28580333 is a prime.

It is a super-2 number, since 2×28582381² = 1633905007258322, 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 28582381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28582387) 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, 14291190 + 14291191.

It is an arithmetic number, because the mean of its divisors is an integer number (14291191).

Almost surely, 2^28582381 is an apocalyptic number.

It is an amenable number.

28582381 is a deficient number, since it is larger than the sum of its proper divisors (1).

28582381 is an equidigital number, since it uses as much as digits as its factorization.

28582381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 37.

The square root of 28582381 is about 5346.2492459667. The cubic root of 28582381 is about 305.7497669474.

The spelling of 28582381 in words is "twenty-eight million, five hundred eighty-two thousand, three hundred eighty-one".