28344921 has 16 divisors (see below), whose sum is σ = 41342400. Its totient is φ = 17131520.

The previous prime is 28344917. The next prime is 28344929. The reversal of 28344921 is 12944382.

It is a cyclic number.

It is not a de Polignac number, because 28344921 - 2² = 28344917 is a prime.

It is a super-3 number, since 3×28344921³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (28344929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13861 + ... + 15773.

It is an arithmetic number, because the mean of its divisors is an integer number (2583900).

Almost surely, 2^28344921 is an apocalyptic number.

It is an amenable number.

28344921 is a deficient number, since it is larger than the sum of its proper divisors (12997479).

28344921 is a wasteful number, since it uses less digits than its factorization.

28344921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2376.

The product of its digits is 13824, while the sum is 33.

The square root of 28344921 is about 5323.9948347082. The cubic root of 28344921 is about 304.9006968667.

The spelling of 28344921 in words is "twenty-eight million, three hundred forty-four thousand, nine hundred twenty-one".