28281771 has 24 divisors (see below), whose sum is σ = 48741840. Its totient is φ = 16160256.

The previous prime is 28281769. The next prime is 28281779. The reversal of 28281771 is 17718282.

It is a happy number.

It is not a de Polignac number, because 28281771 - 2¹ = 28281769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28281779) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9366 + ... + 12011.

It is an arithmetic number, because the mean of its divisors is an integer number (2030910).

Almost surely, 2^28281771 is an apocalyptic number.

28281771 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28281771 is a deficient number, since it is larger than the sum of its proper divisors (20460069).

28281771 is a wasteful number, since it uses less digits than its factorization.

28281771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21400 (or 21387 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 28281771 is about 5318.0608307916. The cubic root of 28281771 is about 304.6740978247.

The spelling of 28281771 in words is "twenty-eight million, two hundred eighty-one thousand, seven hundred seventy-one".