28172851 has 4 divisors (see below), whose sum is σ = 32197552. Its totient is φ = 24148152.

The previous prime is 28172849. The next prime is 28172857. The reversal of 28172851 is 15827182.

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

It is not a de Polignac number, because 28172851 - 2¹ = 28172849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28172857) 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, 2012340 + ... + 2012353.

It is an arithmetic number, because the mean of its divisors is an integer number (8049388).

Almost surely, 2^28172851 is an apocalyptic number.

28172851 is a deficient number, since it is larger than the sum of its proper divisors (4024701).

28172851 is an equidigital number, since it uses as much as digits as its factorization.

28172851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4024700.

The product of its digits is 8960, while the sum is 34.

The square root of 28172851 is about 5307.8103771706. The cubic root of 28172851 is about 304.2824698814.

The spelling of 28172851 in words is "twenty-eight million, one hundred seventy-two thousand, eight hundred fifty-one".