28240238 has 16 divisors (see below), whose sum is σ = 45895920. Its totient is φ = 13031928.

The previous prime is 28240237. The next prime is 28240241. The reversal of 28240238 is 83204282.

It is a super-2 number, since 2×28240238² = 1595022084593288, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28240238.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28240237) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1181 + ... + 7607.

It is an arithmetic number, because the mean of its divisors is an integer number (2868495).

Almost surely, 2^28240238 is an apocalyptic number.

28240238 is a deficient number, since it is larger than the sum of its proper divisors (17655682).

28240238 is an equidigital number, since it uses as much as digits as its factorization.

28240238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6468 (or 6442 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 28240238 is about 5314.1544953078. The cubic root of 28240238 is about 304.5248824085.

The spelling of 28240238 in words is "twenty-eight million, two hundred forty thousand, two hundred thirty-eight".