28687820 has 24 divisors (see below), whose sum is σ = 68851104. Its totient is φ = 9835776.

The previous prime is 28687817. The next prime is 28687843. The reversal of 28687820 is 2878682.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102317 + ... + 102596.

It is an arithmetic number, because the mean of its divisors is an integer number (2868796).

Almost surely, 2^28687820 is an apocalyptic number.

28687820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28687820 is an abundant number, since it is smaller than the sum of its proper divisors (40163284).

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

28687820 is a wasteful number, since it uses less digits than its factorization.

28687820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204929 (or 204927 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 41.

The square root of 28687820 is about 5356.1011939656. The cubic root of 28687820 is about 306.1252708789.

The spelling of 28687820 in words is "twenty-eight million, six hundred eighty-seven thousand, eight hundred twenty".