28131851 has 4 divisors (see below), whose sum is σ = 30689304. Its totient is φ = 25574400.

The previous prime is 28131841. The next prime is 28131853. The reversal of 28131851 is 15813182.

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 28131851 - 2¹⁰ = 28130827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28131853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1278710 + ... + 1278731.

It is an arithmetic number, because the mean of its divisors is an integer number (7672326).

Almost surely, 2^28131851 is an apocalyptic number.

28131851 is a deficient number, since it is larger than the sum of its proper divisors (2557453).

28131851 is a wasteful number, since it uses less digits than its factorization.

28131851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2557452.

The product of its digits is 1920, while the sum is 29.

The square root of 28131851 is about 5303.9467380433. The cubic root of 28131851 is about 304.1347906130.

It can be divided in two parts, 28131 and 851, that added together give a palindrome (28982).

The spelling of 28131851 in words is "twenty-eight million, one hundred thirty-one thousand, eight hundred fifty-one".