28381469 has 4 divisors (see below), whose sum is σ = 28781280. Its totient is φ = 27981660.

The previous prime is 28381453. The next prime is 28381511. The reversal of 28381469 is 96418382.

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, and also an emirpimes, since its reverse is a distinct semiprime: 96418382 = 2 ⋅48209191.

It is a cyclic number.

It is not a de Polignac number, because 28381469 - 2⁴ = 28381453 is a prime.

It is a super-2 number, since 2×28381469² = 1611015565195922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28381439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199799 + ... + 199940.

It is an arithmetic number, because the mean of its divisors is an integer number (7195320).

Almost surely, 2^28381469 is an apocalyptic number.

It is an amenable number.

28381469 is a deficient number, since it is larger than the sum of its proper divisors (399811).

28381469 is an equidigital number, since it uses as much as digits as its factorization.

28381469 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399810.

The product of its digits is 82944, while the sum is 41.

The square root of 28381469 is about 5327.4261139879. The cubic root of 28381469 is about 305.0316871136.

The spelling of 28381469 in words is "twenty-eight million, three hundred eighty-one thousand, four hundred sixty-nine".