28071807 has 4 divisors (see below), whose sum is σ = 37429080. Its totient is φ = 18714536.

The previous prime is 28071761. The next prime is 28071809. The reversal of 28071807 is 70817082.

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 28071807 - 2¹¹ = 28069759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28071809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4678632 + ... + 4678637.

It is an arithmetic number, because the mean of its divisors is an integer number (9357270).

Almost surely, 2^28071807 is an apocalyptic number.

28071807 is a deficient number, since it is larger than the sum of its proper divisors (9357273).

28071807 is an equidigital number, since it uses as much as digits as its factorization.

28071807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9357272.

The product of its (nonzero) digits is 6272, while the sum is 33.

The square root of 28071807 is about 5298.2834012537. The cubic root of 28071807 is about 303.9182569636.

Adding to 28071807 its reverse (70817082), we get a palindrome (98888889).

The spelling of 28071807 in words is "twenty-eight million, seventy-one thousand, eight hundred seven".