28387403 has 4 divisors (see below), whose sum is σ = 30968088. Its totient is φ = 25806720.

The previous prime is 28387393. The next prime is 28387409. The reversal of 28387403 is 30478382.

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 28387403 - 2⁶ = 28387339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28387409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1290326 + ... + 1290347.

It is an arithmetic number, because the mean of its divisors is an integer number (7742022).

Almost surely, 2^28387403 is an apocalyptic number.

28387403 is a deficient number, since it is larger than the sum of its proper divisors (2580685).

28387403 is a wasteful number, since it uses less digits than its factorization.

28387403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2580684.

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 28387403 is about 5327.9830142372. The cubic root of 28387403 is about 305.0529443161.

The spelling of 28387403 in words is "twenty-eight million, three hundred eighty-seven thousand, four hundred three".