28442009 has 2 divisors, whose sum is σ = 28442010. Its totient is φ = 28442008.

The previous prime is 28441981. The next prime is 28442027. The reversal of 28442009 is 90024482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27793984 + 648025 = 5272^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 28442009 - 2⁸ = 28441753 is a prime.

It is equal to p_1767215 and since 28442009 and 1767215 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28442039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14221004 + 14221005.

It is an arithmetic number, because the mean of its divisors is an integer number (14221005).

Almost surely, 2^28442009 is an apocalyptic number.

It is an amenable number.

28442009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28442009 is an equidigital number, since it uses as much as digits as its factorization.

28442009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 28442009 is about 5333.1050055291. The cubic root of 28442009 is about 305.2484189491.

The spelling of 28442009 in words is "twenty-eight million, four hundred forty-two thousand, nine".