28781487 has 40 divisors (see below), whose sum is σ = 51296256. Its totient is φ = 15724368.

The previous prime is 28781477. The next prime is 28781497. The reversal of 28781487 is 78418782.

It is an interprime number because it is at equal distance from previous prime (28781477) and next prime (28781497).

It is not a de Polignac number, because 28781487 - 2⁴ = 28781471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11938 + ... + 14144.

Almost surely, 2^28781487 is an apocalyptic number.

28781487 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28781487 is a deficient number, since it is larger than the sum of its proper divisors (22514769).

28781487 is a wasteful number, since it uses less digits than its factorization.

28781487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2249 (or 2240 counting only the distinct ones).

The product of its digits is 200704, while the sum is 45.

The square root of 28781487 is about 5364.8380217859. The cubic root of 28781487 is about 306.4580797750.

The spelling of 28781487 in words is "twenty-eight million, seven hundred eighty-one thousand, four hundred eighty-seven".