28005207 has 4 divisors (see below), whose sum is σ = 37340280. Its totient is φ = 18670136.

The previous prime is 28005203. The next prime is 28005227. The reversal of 28005207 is 70250082.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28005207 - 2² = 28005203 is a prime.

It is a super-2 number, since 2×28005207² = 1568583238225698, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28005203) 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, 4667532 + ... + 4667537.

It is an arithmetic number, because the mean of its divisors is an integer number (9335070).

Almost surely, 2^28005207 is an apocalyptic number.

28005207 is a deficient number, since it is larger than the sum of its proper divisors (9335073).

28005207 is an equidigital number, since it uses as much as digits as its factorization.

28005207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9335072.

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 28005207 is about 5291.9946145097. The cubic root of 28005207 is about 303.6777192575.

Adding to 28005207 its reverse (70250082), we get a palindrome (98255289).

The spelling of 28005207 in words is "twenty-eight million, five thousand, two hundred seven".