28243971 has 40 divisors (see below), whose sum is σ = 48767840. Its totient is φ = 15956352.

The previous prime is 28243961. The next prime is 28243973. The reversal of 28243971 is 17934282.

It is not a de Polignac number, because 28243971 - 2⁶ = 28243907 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

Its product of digits (24192) is a multiple of the sum of its prime divisors (576).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28243973) 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 39 ways as a sum of consecutive naturals, for example, 61575 + ... + 62031.

It is an arithmetic number, because the mean of its divisors is an integer number (1219196).

Almost surely, 2^28243971 is an apocalyptic number.

28243971 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28243971 is a deficient number, since it is larger than the sum of its proper divisors (20523869).

28243971 is a wasteful number, since it uses less digits than its factorization.

28243971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585 (or 576 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 28243971 is about 5314.5057154923. The cubic root of 28243971 is about 304.5382999217.

It can be divided in two parts, 282 and 43971, that added together give a triangular number (44253 = T₂₉₇).

The spelling of 28243971 in words is "twenty-eight million, two hundred forty-three thousand, nine hundred seventy-one".