28384561 has 4 divisors (see below), whose sum is σ = 29300224. Its totient is φ = 27468900.

The previous prime is 28384549. The next prime is 28384571. The reversal of 28384561 is 16548382.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28384561 - 2⁵ = 28384529 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28384561.

It is not an unprimeable number, because it can be changed into a prime (28384571) 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, 457785 + ... + 457846.

It is an arithmetic number, because the mean of its divisors is an integer number (7325056).

Almost surely, 2^28384561 is an apocalyptic number.

It is an amenable number.

28384561 is a deficient number, since it is larger than the sum of its proper divisors (915663).

28384561 is an equidigital number, since it uses as much as digits as its factorization.

28384561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915662.

The product of its digits is 46080, while the sum is 37.

The square root of 28384561 is about 5327.7163025071. The cubic root of 28384561 is about 305.0427638686.

The spelling of 28384561 in words is "twenty-eight million, three hundred eighty-four thousand, five hundred sixty-one".