28505384 has 16 divisors (see below), whose sum is σ = 53634420. Its totient is φ = 14202880.

The previous prime is 28505381. The next prime is 28505387. The reversal of 28505384 is 48350582.

28505384 = 747² + 748² + ... + 794².

It is an interprime number because it is at equal distance from previous prime (28505381) and next prime (28505387).

It can be written as a sum of positive squares in 2 ways, for example, as 27984100 + 521284 = 5290^2 + 722^2 .

It is not an unprimeable number, because it can be changed into a prime (28505381) 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, 3737 + ... + 8424.

Almost surely, 2^28505384 is an apocalyptic number.

It is an amenable number.

28505384 is a deficient number, since it is larger than the sum of its proper divisors (25129036).

28505384 is a wasteful number, since it uses less digits than its factorization.

28505384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12460 (or 12456 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 35.

The square root of 28505384 is about 5339.0433600037. The cubic root of 28505384 is about 305.4749707834.

The spelling of 28505384 in words is "twenty-eight million, five hundred five thousand, three hundred eighty-four".