28033997 has 4 divisors (see below), whose sum is σ = 28371840. Its totient is φ = 27696156.

The previous prime is 28033991. The next prime is 28034009. The reversal of 28033997 is 79933082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28033997 - 2⁶ = 28033933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28033991) 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, 168797 + ... + 168962.

It is an arithmetic number, because the mean of its divisors is an integer number (7092960).

Almost surely, 2^28033997 is an apocalyptic number.

It is an amenable number.

28033997 is a deficient number, since it is larger than the sum of its proper divisors (337843).

28033997 is an equidigital number, since it uses as much as digits as its factorization.

28033997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337842.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 28033997 is about 5294.7140621567. The cubic root of 28033997 is about 303.7817461894.

The spelling of 28033997 in words is "twenty-eight million, thirty-three thousand, nine hundred ninety-seven".