28189998 has 16 divisors (see below), whose sum is σ = 62644560. Its totient is φ = 9396648.

The previous prime is 28189981. The next prime is 28190017. The reversal of 28189998 is 89998182.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 522037 = 28189998 / (2 + 8 + 1 + 8 + 9 + 9 + 9 + 8).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 260965 + ... + 261072.

It is an arithmetic number, because the mean of its divisors is an integer number (3915285).

Almost surely, 2^28189998 is an apocalyptic number.

28189998 is an abundant number, since it is smaller than the sum of its proper divisors (34454562).

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

28189998 is a wasteful number, since it uses less digits than its factorization.

28189998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522048 (or 522042 counting only the distinct ones).

The product of its digits is 746496, while the sum is 54.

The square root of 28189998 is about 5309.4253926390. The cubic root of 28189998 is about 304.3441897424.

The spelling of 28189998 in words is "twenty-eight million, one hundred eighty-nine thousand, nine hundred ninety-eight".