28450640 has 20 divisors (see below), whose sum is σ = 66147924. Its totient is φ = 11380224.

The previous prime is 28450633. The next prime is 28450663. The reversal of 28450640 is 4605482.

It can be written as a sum of positive squares in 2 ways, for example, as 6697744 + 21752896 = 2588^2 + 4664^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177737 + ... + 177896.

Almost surely, 2^28450640 is an apocalyptic number.

28450640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28450640 is an abundant number, since it is smaller than the sum of its proper divisors (37697284).

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

28450640 is a wasteful number, since it uses less digits than its factorization.

28450640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355646 (or 355640 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 28450640 is about 5333.9141350419. The cubic root of 28450640 is about 305.2792926783.

The spelling of 28450640 in words is "twenty-eight million, four hundred fifty thousand, six hundred forty".