28333921 has 32 divisors (see below), whose sum is σ = 37739520. Its totient is φ = 20606400.

The previous prime is 28333901. The next prime is 28333933. The reversal of 28333921 is 12933382.

It is a cyclic number.

It is not a de Polignac number, because 28333921 - 2⁵ = 28333889 is a prime.

It is a super-2 number, since 2×28333921² = 1605622158468482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28333901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 156451 + ... + 156631.

It is an arithmetic number, because the mean of its divisors is an integer number (1179360).

Almost surely, 2^28333921 is an apocalyptic number.

It is an amenable number.

28333921 is a deficient number, since it is larger than the sum of its proper divisors (9405599).

28333921 is a wasteful number, since it uses less digits than its factorization.

28333921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325.

The product of its digits is 7776, while the sum is 31.

The square root of 28333921 is about 5322.9616756088. The cubic root of 28333921 is about 304.8612501569.

The spelling of 28333921 in words is "twenty-eight million, three hundred thirty-three thousand, nine hundred twenty-one".