28691441 has 4 divisors (see below), whose sum is σ = 28729332. Its totient is φ = 28653552.

The previous prime is 28691417. The next prime is 28691483. The reversal of 28691441 is 14419682.

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: 14419682 = 2 ⋅7209841.

It can be written as a sum of positive squares in 2 ways, for example, as 8179600 + 20511841 = 2860^2 + 4529^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28691441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28691401) 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, 17786 + ... + 19331.

It is an arithmetic number, because the mean of its divisors is an integer number (7182333).

Almost surely, 2^28691441 is an apocalyptic number.

It is an amenable number.

28691441 is a deficient number, since it is larger than the sum of its proper divisors (37891).

28691441 is an equidigital number, since it uses as much as digits as its factorization.

28691441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37890.

The product of its digits is 13824, while the sum is 35.

The square root of 28691441 is about 5356.4392090268. The cubic root of 28691441 is about 306.1381501307.

The spelling of 28691441 in words is "twenty-eight million, six hundred ninety-one thousand, four hundred forty-one".