28217538 has 32 divisors (see below), whose sum is σ = 63073920. Its totient is φ = 9350640.

The previous prime is 28217537. The next prime is 28217543. The reversal of 28217538 is 83571282.

It is not an unprimeable number, because it can be changed into a prime (28217537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8331 + ... + 11217.

It is an arithmetic number, because the mean of its divisors is an integer number (1971060).

Almost surely, 2^28217538 is an apocalyptic number.

28217538 is an abundant number, since it is smaller than the sum of its proper divisors (34856382).

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

28217538 is a wasteful number, since it uses less digits than its factorization.

28217538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3079 (or 3073 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28217538 is about 5312.0182605108. The cubic root of 28217538 is about 304.4432663843.

The spelling of 28217538 in words is "twenty-eight million, two hundred seventeen thousand, five hundred thirty-eight".