28267281 has 12 divisors (see below), whose sum is σ = 46663552. Its totient is φ = 16152696.

The previous prime is 28267273. The next prime is 28267303. The reversal of 28267281 is 18276282.

It is a happy number.

It is not a de Polignac number, because 28267281 - 2³ = 28267273 is a prime.

It is a super-2 number, since 2×28267281² = 1598078350265922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28267241) 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 11 ways as a sum of consecutive naturals, for example, 224281 + ... + 224406.

Almost surely, 2^28267281 is an apocalyptic number.

28267281 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28267281 is a deficient number, since it is larger than the sum of its proper divisors (18396271).

28267281 is a wasteful number, since it uses less digits than its factorization.

28267281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448700 (or 448697 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 28267281 is about 5316.6983175651. The cubic root of 28267281 is about 304.6220562718.

Subtracting from 28267281 its reverse (18276282), we obtain a palindrome (9990999).

The spelling of 28267281 in words is "twenty-eight million, two hundred sixty-seven thousand, two hundred eighty-one".