28078261 has 2 divisors, whose sum is σ = 28078262. Its totient is φ = 28078260.

The previous prime is 28078243. The next prime is 28078273. The reversal of 28078261 is 16287082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16728100 + 11350161 = 4090^2 + 3369^2 .

It is a cyclic number.

It is not a de Polignac number, because 28078261 - 2⁵ = 28078229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28078861) 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, 14039130 + 14039131.

It is an arithmetic number, because the mean of its divisors is an integer number (14039131).

Almost surely, 2^28078261 is an apocalyptic number.

It is an amenable number.

28078261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28078261 is an equidigital number, since it uses as much as digits as its factorization.

28078261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 28078261 is about 5298.8924314426. The cubic root of 28078261 is about 303.9415465001.

The spelling of 28078261 in words is "twenty-eight million, seventy-eight thousand, two hundred sixty-one".