28933421 has 8 divisors (see below), whose sum is σ = 31871424. Its totient is φ = 26046720.

The previous prime is 28933403. The next prime is 28933427. The reversal of 28933421 is 12433982.

It is a happy number.

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 28933421 - 2⁶ = 28933357 is a prime.

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 (28933427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11636 + ... + 13901.

It is an arithmetic number, because the mean of its divisors is an integer number (3983928).

Almost surely, 2^28933421 is an apocalyptic number.

It is an amenable number.

28933421 is a deficient number, since it is larger than the sum of its proper divisors (2938003).

28933421 is a wasteful number, since it uses less digits than its factorization.

28933421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25651.

The product of its digits is 10368, while the sum is 32.

The square root of 28933421 is about 5378.9795500634. The cubic root of 28933421 is about 306.9963854186.

The spelling of 28933421 in words is "twenty-eight million, nine hundred thirty-three thousand, four hundred twenty-one".