28249040 has 40 divisors (see below), whose sum is σ = 65971968. Its totient is φ = 11249280.

The previous prime is 28249031. The next prime is 28249049. The reversal of 28249040 is 4094282.

It is an interprime number because it is at equal distance from previous prime (28249031) and next prime (28249049).

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 28248994 and 28249012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28249049) 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 7 ways as a sum of consecutive naturals, for example, 21029 + ... + 22331.

Almost surely, 2^28249040 is an apocalyptic number.

28249040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28249040 is an abundant number, since it is smaller than the sum of its proper divisors (37722928).

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

28249040 is a wasteful number, since it uses less digits than its factorization.

28249040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587 (or 1581 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 28249040 is about 5314.9825963967. The cubic root of 28249040 is about 304.5565175241.

The spelling of 28249040 in words is "twenty-eight million, two hundred forty-nine thousand, forty".