28912236820 has 12 divisors (see below), whose sum is σ = 60715697364. Its totient is φ = 11564894720.

The previous prime is 28912236797. The next prime is 28912236851. The reversal of 28912236820 is 2863221982.

It can be written as a sum of positive squares in 2 ways, for example, as 9873204496 + 19039032324 = 99364^2 + 137982^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 722805901 + ... + 722805940.

It is an arithmetic number, because the mean of its divisors is an integer number (5059641447).

Almost surely, 2^28912236820 is an apocalyptic number.

28912236820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28912236820 is an abundant number, since it is smaller than the sum of its proper divisors (31803460544).

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

28912236820 is a wasteful number, since it uses less digits than its factorization.

28912236820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445611850 (or 1445611848 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The spelling of 28912236820 in words is "twenty-eight billion, nine hundred twelve million, two hundred thirty-six thousand, eight hundred twenty".