28957807 has 4 divisors (see below), whose sum is σ = 28976080. Its totient is φ = 28939536.

The previous prime is 28957801. The next prime is 28957823. The reversal of 28957807 is 70875982.

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 28957807 - 2⁷ = 28957679 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 (28957801) 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, 6507 + ... + 10012.

It is an arithmetic number, because the mean of its divisors is an integer number (7244020).

Almost surely, 2^28957807 is an apocalyptic number.

28957807 is a deficient number, since it is larger than the sum of its proper divisors (18273).

28957807 is a wasteful number, since it uses less digits than its factorization.

28957807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18272.

The product of its (nonzero) digits is 282240, while the sum is 46.

The square root of 28957807 is about 5381.2458594641. The cubic root of 28957807 is about 307.0826099451.

The spelling of 28957807 in words is "twenty-eight million, nine hundred fifty-seven thousand, eight hundred seven".