28619009 has 4 divisors (see below), whose sum is σ = 28630740. Its totient is φ = 28607280.

The previous prime is 28618999. The next prime is 28619011. The reversal of 28619009 is 90091682.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90091682 = 2 ⋅45045841.

It can be written as a sum of positive squares in 2 ways, for example, as 16785409 + 11833600 = 4097^2 + 3440^2 .

It is a cyclic number.

It is not a de Polignac number, because 28619009 - 2⁸ = 28618753 is a prime.

It is a super-2 number, since 2×28619009² = 1638095352284162, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28619009.

It is not an unprimeable number, because it can be changed into a prime (28619029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 674 + ... + 7595.

It is an arithmetic number, because the mean of its divisors is an integer number (7157685).

Almost surely, 2^28619009 is an apocalyptic number.

It is an amenable number.

28619009 is a deficient number, since it is larger than the sum of its proper divisors (11731).

28619009 is an equidigital number, since it uses as much as digits as its factorization.

28619009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11730.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 28619009 is about 5349.6737283689. The cubic root of 28619009 is about 305.8803161607.

The spelling of 28619009 in words is "twenty-eight million, six hundred nineteen thousand, nine".