28478031 has 4 divisors (see below), whose sum is σ = 37970712. Its totient is φ = 18985352.

The previous prime is 28478003. The next prime is 28478039. The reversal of 28478031 is 13087482.

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 28478031 - 2¹¹ = 28475983 is a prime.

It is a super-2 number, since 2×28478031² = 1621996499273922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28477983 and 28478001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28478039) 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 3 ways as a sum of consecutive naturals, for example, 4746336 + ... + 4746341.

It is an arithmetic number, because the mean of its divisors is an integer number (9492678).

Almost surely, 2^28478031 is an apocalyptic number.

28478031 is a deficient number, since it is larger than the sum of its proper divisors (9492681).

28478031 is an equidigital number, since it uses as much as digits as its factorization.

28478031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9492680.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 28478031 is about 5336.4811439749. The cubic root of 28478031 is about 305.3772309912.

It can be divided in two parts, 2847 and 8031, that added together give a triangular number (10878 = T₁₄₇).

The spelling of 28478031 in words is "twenty-eight million, four hundred seventy-eight thousand, thirty-one".