28398426 has 48 divisors (see below), whose sum is σ = 68543424. Its totient is φ = 7682688.

The previous prime is 28398413. The next prime is 28398427. The reversal of 28398426 is 62489382.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28398427) 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 23 ways as a sum of consecutive naturals, for example, 14226 + ... + 16098.

It is an arithmetic number, because the mean of its divisors is an integer number (1427988).

Almost surely, 2^28398426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28398426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34271712).

28398426 is an abundant number, since it is smaller than the sum of its proper divisors (40144998).

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

28398426 is a wasteful number, since it uses less digits than its factorization.

28398426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1923 (or 1904 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 28398426 is about 5329.0173578250. The cubic root of 28398426 is about 305.0924238399.

The spelling of 28398426 in words is "twenty-eight million, three hundred ninety-eight thousand, four hundred twenty-six".