28780249 has 2 divisors, whose sum is σ = 28780250. Its totient is φ = 28780248.

The previous prime is 28780247. The next prime is 28780261. The reversal of 28780249 is 94208782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24651225 + 4129024 = 4965^2 + 2032^2 .

It is a cyclic number.

It is not a de Polignac number, because 28780249 - 2¹ = 28780247 is a prime.

Together with 28780247, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28780247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14390124 + 14390125.

It is an arithmetic number, because the mean of its divisors is an integer number (14390125).

Almost surely, 2^28780249 is an apocalyptic number.

It is an amenable number.

28780249 is a deficient number, since it is larger than the sum of its proper divisors (1).

28780249 is an equidigital number, since it uses as much as digits as its factorization.

28780249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 28780249 is about 5364.7226396152. The cubic root of 28780249 is about 306.4536857405.

The spelling of 28780249 in words is "twenty-eight million, seven hundred eighty thousand, two hundred forty-nine".