27120819856 has 45 divisors (see below), whose sum is σ = 56917532361. Its totient is φ = 12513349056.

The previous prime is 27120819853. The next prime is 27120819881. The reversal of 27120819856 is 65891802172.

It is a happy number.

The square root of 27120819856 is 164684.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4011955600 + 23108864256 = 63340^2 + 152016^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27120819853) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8561985 + ... + 8565151.

Almost surely, 2^27120819856 is an apocalyptic number.

27120819856 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

27120819856 is the 164684-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27120819856

27120819856 is an abundant number, since it is smaller than the sum of its proper divisors (29796712505).

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

27120819856 is an frugal number, since it uses more digits than its factorization.

27120819856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6368 (or 3182 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 49.

Multiplying 27120819856 by its sum of digits (49), we get a square (1328920172944 = 1152788²).

The spelling of 27120819856 in words is "twenty-seven billion, one hundred twenty million, eight hundred nineteen thousand, eight hundred fifty-six".