28915261 has 2 divisors, whose sum is σ = 28915262. Its totient is φ = 28915260.

The previous prime is 28915259. The next prime is 28915309. The reversal of 28915261 is 16251982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25190361 + 3724900 = 5019^2 + 1930^2 .

It is a cyclic number.

It is not a de Polignac number, because 28915261 - 2¹ = 28915259 is a prime.

Together with 28915259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28915361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14457630 + 14457631.

It is an arithmetic number, because the mean of its divisors is an integer number (14457631).

Almost surely, 2^28915261 is an apocalyptic number.

It is an amenable number.

28915261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28915261 is an equidigital number, since it uses as much as digits as its factorization.

28915261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 34.

The square root of 28915261 is about 5377.2912325817. The cubic root of 28915261 is about 306.9321434341.

The spelling of 28915261 in words is "twenty-eight million, nine hundred fifteen thousand, two hundred sixty-one".