28308649 has 2 divisors, whose sum is σ = 28308650. Its totient is φ = 28308648.

The previous prime is 28308629. The next prime is 28308667. The reversal of 28308649 is 94680382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28164249 + 144400 = 5307^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 28308649 - 2⁷ = 28308521 is a prime.

It is a super-3 number, since 3×28308649³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (28308619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14154324 + 14154325.

It is an arithmetic number, because the mean of its divisors is an integer number (14154325).

Almost surely, 2^28308649 is an apocalyptic number.

It is an amenable number.

28308649 is a deficient number, since it is larger than the sum of its proper divisors (1).

28308649 is an equidigital number, since it uses as much as digits as its factorization.

28308649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 28308649 is about 5320.5872796149. The cubic root of 28308649 is about 304.7705844460.

The spelling of 28308649 in words is "twenty-eight million, three hundred eight thousand, six hundred forty-nine".