28278521500 has 24 divisors (see below), whose sum is σ = 61760292048. Its totient is φ = 11311408400.

The previous prime is 28278521489. The next prime is 28278521543. The reversal of 28278521500 is 512587282.

It is a congruent number.

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, 28278022 + ... + 28279021.

It is an arithmetic number, because the mean of its divisors is an integer number (2573345502).

Almost surely, 2^28278521500 is an apocalyptic number.

28278521500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28278521500 is an abundant number, since it is smaller than the sum of its proper divisors (33481770548).

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

28278521500 is a wasteful number, since it uses less digits than its factorization.

28278521500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56557062 (or 56557050 counting only the distinct ones).

The product of its (nonzero) digits is 89600, while the sum is 40.

The spelling of 28278521500 in words is "twenty-eight billion, two hundred seventy-eight million, five hundred twenty-one thousand, five hundred".