28481669 has 4 divisors (see below), whose sum is σ = 28626444. Its totient is φ = 28336896.

The previous prime is 28481657. The next prime is 28481689. The reversal of 28481669 is 96618482.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96618482 = 2 ⋅48309241.

It can be written as a sum of positive squares in 2 ways, for example, as 18809569 + 9672100 = 4337^2 + 3110^2 .

It is a cyclic number.

It is not a de Polignac number, because 28481669 - 2¹² = 28477573 is a prime.

It is a super-2 number, since 2×28481669² = 1622410938051122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28481639) 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, 72092 + ... + 72485.

It is an arithmetic number, because the mean of its divisors is an integer number (7156611).

Almost surely, 2^28481669 is an apocalyptic number.

It is an amenable number.

28481669 is a deficient number, since it is larger than the sum of its proper divisors (144775).

28481669 is a wasteful number, since it uses less digits than its factorization.

28481669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144774.

The product of its digits is 165888, while the sum is 44.

The square root of 28481669 is about 5336.8219944083. The cubic root of 28481669 is about 305.3902341732.

The spelling of 28481669 in words is "twenty-eight million, four hundred eighty-one thousand, six hundred sixty-nine".