28204087 has 4 divisors (see below), whose sum is σ = 28860040. Its totient is φ = 27548136.

The previous prime is 28204081. The next prime is 28204091. The reversal of 28204087 is 78040282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78040282 = 2 ⋅39020141.

It is a cyclic number.

It is not a de Polignac number, because 28204087 - 2¹¹ = 28202039 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 (28204081) 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, 327912 + ... + 327997.

It is an arithmetic number, because the mean of its divisors is an integer number (7215010).

Almost surely, 2^28204087 is an apocalyptic number.

28204087 is a deficient number, since it is larger than the sum of its proper divisors (655953).

28204087 is an equidigital number, since it uses as much as digits as its factorization.

28204087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655952.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 28204087 is about 5310.7520183115. The cubic root of 28204087 is about 304.3948837408.

The spelling of 28204087 in words is "twenty-eight million, two hundred four thousand, eighty-seven".