28689649 has 2 divisors, whose sum is σ = 28689650. Its totient is φ = 28689648.

The previous prime is 28689623. The next prime is 28689667. The reversal of 28689649 is 94698682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21762225 + 6927424 = 4665^2 + 2632^2 .

It is a cyclic number.

It is not a de Polignac number, because 28689649 - 2⁹ = 28689137 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28689596 and 28689605.

It is not a weakly prime, because it can be changed into another prime (28689679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14344824 + 14344825.

It is an arithmetic number, because the mean of its divisors is an integer number (14344825).

Almost surely, 2^28689649 is an apocalyptic number.

It is an amenable number.

28689649 is a deficient number, since it is larger than the sum of its proper divisors (1).

28689649 is an equidigital number, since it uses as much as digits as its factorization.

28689649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 52.

The square root of 28689649 is about 5356.2719311103. The cubic root of 28689649 is about 306.1317764414.

The spelling of 28689649 in words is "twenty-eight million, six hundred eighty-nine thousand, six hundred forty-nine".