28447291 has 2 divisors, whose sum is σ = 28447292. Its totient is φ = 28447290.

The previous prime is 28447283. The next prime is 28447327. The reversal of 28447291 is 19274482.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28447291 - 2³ = 28447283 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28447291.

It is not a weakly prime, because it can be changed into another prime (28447201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14223645 + 14223646.

It is an arithmetic number, because the mean of its divisors is an integer number (14223646).

Almost surely, 2^28447291 is an apocalyptic number.

28447291 is a deficient number, since it is larger than the sum of its proper divisors (1).

28447291 is an equidigital number, since it uses as much as digits as its factorization.

28447291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 37.

The square root of 28447291 is about 5333.6001912404. The cubic root of 28447291 is about 305.2673137975.

The spelling of 28447291 in words is "twenty-eight million, four hundred forty-seven thousand, two hundred ninety-one".