28735640 has 16 divisors (see below), whose sum is σ = 64655280. Its totient is φ = 11494240.

The previous prime is 28735639. The next prime is 28735649. The reversal of 28735640 is 4653782.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 28735640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28735649) 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, 359156 + ... + 359235.

It is an arithmetic number, because the mean of its divisors is an integer number (4040955).

Almost surely, 2^28735640 is an apocalyptic number.

28735640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28735640 is an abundant number, since it is smaller than the sum of its proper divisors (35919640).

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

28735640 is a wasteful number, since it uses less digits than its factorization.

28735640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718402 (or 718398 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 28735640 is about 5360.5634032254. The cubic root of 28735640 is about 306.2952708308.

The spelling of 28735640 in words is "twenty-eight million, seven hundred thirty-five thousand, six hundred forty".