28238658 has 16 divisors (see below), whose sum is σ = 64545600. Its totient is φ = 8068176.

The previous prime is 28238653. The next prime is 28238671. The reversal of 28238658 is 85683282.

It is a super-4 number, since 4×28238658⁴ (a number of 31 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 672349 = 28238658 / (2 + 8 + 2 + 3 + 8 + 6 + 5 + 8).

It is not an unprimeable number, because it can be changed into a prime (28238653) 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 7 ways as a sum of consecutive naturals, for example, 336133 + ... + 336216.

It is an arithmetic number, because the mean of its divisors is an integer number (4034100).

Almost surely, 2^28238658 is an apocalyptic number.

28238658 is an abundant number, since it is smaller than the sum of its proper divisors (36306942).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28238658 is a wasteful number, since it uses less digits than its factorization.

28238658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672361.

The product of its digits is 184320, while the sum is 42.

The square root of 28238658 is about 5314.0058336438. The cubic root of 28238658 is about 304.5192030620.

The spelling of 28238658 in words is "twenty-eight million, two hundred thirty-eight thousand, six hundred fifty-eight".