28440238 has 8 divisors (see below), whose sum is σ = 42753888. Its totient is φ = 14188944.

The previous prime is 28440221. The next prime is 28440239. The reversal of 28440238 is 83204482.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28440239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14431 + ... + 16282.

It is an arithmetic number, because the mean of its divisors is an integer number (5344236).

Almost surely, 2^28440238 is an apocalyptic number.

28440238 is a deficient number, since it is larger than the sum of its proper divisors (14313650).

28440238 is a wasteful number, since it uses less digits than its factorization.

28440238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31178.

The product of its (nonzero) digits is 12288, while the sum is 31.

The square root of 28440238 is about 5332.9389645860. The cubic root of 28440238 is about 305.2420831780.

The spelling of 28440238 in words is "twenty-eight million, four hundred forty thousand, two hundred thirty-eight".