28478987 has 4 divisors (see below), whose sum is σ = 29397696. Its totient is φ = 27560280.

The previous prime is 28478977. The next prime is 28479041. The reversal of 28478987 is 78987482.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28478987 - 2⁴ = 28478971 is a prime.

It is a super-2 number, since 2×28478987² = 1622105401092338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28478917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 459308 + ... + 459369.

It is an arithmetic number, because the mean of its divisors is an integer number (7349424).

Almost surely, 2^28478987 is an apocalyptic number.

28478987 is a deficient number, since it is larger than the sum of its proper divisors (918709).

28478987 is an equidigital number, since it uses as much as digits as its factorization.

28478987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918708.

The product of its digits is 1806336, while the sum is 53.

The square root of 28478987 is about 5336.5707153564. The cubic root of 28478987 is about 305.3806480974.

The spelling of 28478987 in words is "twenty-eight million, four hundred seventy-eight thousand, nine hundred eighty-seven".