28921369 has 8 divisors (see below), whose sum is σ = 30701160. Its totient is φ = 27150336.

The previous prime is 28921349. The next prime is 28921397. The reversal of 28921369 is 96312982.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 405769 + 28515600 = 637^2 + 5340^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28921369 - 2⁵ = 28921337 is a prime.

It is a super-2 number, since 2×28921369² = 1672891169668322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28921339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5397 + ... + 9325.

It is an arithmetic number, because the mean of its divisors is an integer number (3837645).

Almost surely, 2^28921369 is an apocalyptic number.

It is an amenable number.

28921369 is a deficient number, since it is larger than the sum of its proper divisors (1779791).

28921369 is a wasteful number, since it uses less digits than its factorization.

28921369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4379.

The product of its digits is 46656, while the sum is 40.

The square root of 28921369 is about 5377.8591465378. The cubic root of 28921369 is about 306.9537538165.

The spelling of 28921369 in words is "twenty-eight million, nine hundred twenty-one thousand, three hundred sixty-nine".