28875551 has 4 divisors (see below), whose sum is σ = 28898952. Its totient is φ = 28852152.

The previous prime is 28875547. The next prime is 28875599. The reversal of 28875551 is 15557882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15557882 = 2 ⋅7778941.

It is a cyclic number.

It is not a de Polignac number, because 28875551 - 2² = 28875547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28875499 and 28875508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28875751) 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, 9740 + ... + 12353.

It is an arithmetic number, because the mean of its divisors is an integer number (7224738).

Almost surely, 2^28875551 is an apocalyptic number.

28875551 is a deficient number, since it is larger than the sum of its proper divisors (23401).

28875551 is a wasteful number, since it uses less digits than its factorization.

28875551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23400.

The product of its digits is 112000, while the sum is 41.

The square root of 28875551 is about 5373.5975844866. The cubic root of 28875551 is about 306.7915733829.

The spelling of 28875551 in words is "twenty-eight million, eight hundred seventy-five thousand, five hundred fifty-one".