28640886 has 32 divisors (see below), whose sum is σ = 62298720. Its totient is φ = 8741376.

The previous prime is 28640863. The next prime is 28640917. The reversal of 28640886 is 68804682.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 21 + ... + 7568.

It is an arithmetic number, because the mean of its divisors is an integer number (1946835).

Almost surely, 2^28640886 is an apocalyptic number.

28640886 is an abundant number, since it is smaller than the sum of its proper divisors (33657834).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28640886 is a wasteful number, since it uses less digits than its factorization.

28640886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7648.

The product of its (nonzero) digits is 147456, while the sum is 42.

The square root of 28640886 is about 5351.7180419002. The cubic root of 28640886 is about 305.9582368567.

The spelling of 28640886 in words is "twenty-eight million, six hundred forty thousand, eight hundred eighty-six".