28278403 has 4 divisors (see below), whose sum is σ = 29766760. Its totient is φ = 26790048.

The previous prime is 28278401. The next prime is 28278409. The reversal of 28278403 is 30487282.

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 28278403 - 2¹ = 28278401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28278401) 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, 744150 + ... + 744187.

It is an arithmetic number, because the mean of its divisors is an integer number (7441690).

Almost surely, 2^28278403 is an apocalyptic number.

28278403 is a deficient number, since it is larger than the sum of its proper divisors (1488357).

28278403 is a wasteful number, since it uses less digits than its factorization.

28278403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1488356.

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 28278403 is about 5317.7441645871. The cubic root of 28278403 is about 304.6620030718.

The spelling of 28278403 in words is "twenty-eight million, two hundred seventy-eight thousand, four hundred three".