28145609 has 2 divisors, whose sum is σ = 28145610. Its totient is φ = 28145608.

The previous prime is 28145603. The next prime is 28145633. The reversal of 28145609 is 90654182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18361225 + 9784384 = 4285^2 + 3128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28145609 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28145603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14072804 + 14072805.

It is an arithmetic number, because the mean of its divisors is an integer number (14072805).

Almost surely, 2^28145609 is an apocalyptic number.

It is an amenable number.

28145609 is a deficient number, since it is larger than the sum of its proper divisors (1).

28145609 is an equidigital number, since it uses as much as digits as its factorization.

28145609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 28145609 is about 5305.2435382365. The cubic root of 28145609 is about 304.1843619988.

The spelling of 28145609 in words is "twenty-eight million, one hundred forty-five thousand, six hundred nine".