28171281 has 32 divisors (see below), whose sum is σ = 41472000. Its totient is φ = 16943040.

The previous prime is 28171277. The next prime is 28171291. The reversal of 28171281 is 18217182.

It is a happy number.

It is not a de Polignac number, because 28171281 - 2² = 28171277 is a prime.

It is a super-2 number, since 2×28171281² = 1587242146361922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28171201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 188995 + ... + 189143.

It is an arithmetic number, because the mean of its divisors is an integer number (1296000).

Almost surely, 2^28171281 is an apocalyptic number.

It is an amenable number.

28171281 is a deficient number, since it is larger than the sum of its proper divisors (13300719).

28171281 is a wasteful number, since it uses less digits than its factorization.

28171281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309.

The product of its digits is 1792, while the sum is 30.

The square root of 28171281 is about 5307.6624798493. The cubic root of 28171281 is about 304.2768174852.

The spelling of 28171281 in words is "twenty-eight million, one hundred seventy-one thousand, two hundred eighty-one".