28115261 has 2 divisors, whose sum is σ = 28115262. Its totient is φ = 28115260.

The previous prime is 28115237. The next prime is 28115267. The reversal of 28115261 is 16251182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16859236 + 11256025 = 4106^2 + 3355^2 .

It is a cyclic number.

It is not a de Polignac number, because 28115261 - 2¹⁸ = 27853117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28115261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28115267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14057630 + 14057631.

It is an arithmetic number, because the mean of its divisors is an integer number (14057631).

Almost surely, 2^28115261 is an apocalyptic number.

It is an amenable number.

28115261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28115261 is an equidigital number, since it uses as much as digits as its factorization.

28115261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 26.

The square root of 28115261 is about 5302.3825776720. The cubic root of 28115261 is about 304.0749937617.

The spelling of 28115261 in words is "twenty-eight million, one hundred fifteen thousand, two hundred sixty-one".