28451540 has 96 divisors (see below), whose sum is σ = 70235424. Its totient is φ = 9584640.

The previous prime is 28451539. The next prime is 28451567. The reversal of 28451540 is 4515482.

It can be written as a sum of positive squares in 16 ways, for example, as 17455684 + 10995856 = 4178^2 + 3316^2 .

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 181142 + ... + 181298.

It is an arithmetic number, because the mean of its divisors is an integer number (731619).

Almost surely, 2^28451540 is an apocalyptic number.

28451540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28451540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35117712).

28451540 is an abundant number, since it is smaller than the sum of its proper divisors (41783884).

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

28451540 is a wasteful number, since it uses less digits than its factorization.

28451540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 28451540 is about 5333.9985001873. The cubic root of 28451540 is about 305.2825116857.

The spelling of 28451540 in words is "twenty-eight million, four hundred fifty-one thousand, five hundred forty".