27991209489800 has 108 divisors (see below), whose sum is σ = 66892623002415. Its totient is φ = 10892798697600.

The previous prime is 27991209489799. The next prime is 27991209489811. The reversal of 27991209489800 is 898490219972.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 22200361899076 + 5790847590724 = 4711726^2 + 2406418^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3741070.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2768386745 + ... + 2768396855.

Almost surely, 2^{27991209489800} is an apocalyptic number.

27991209489800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27991209489800

27991209489800 is an abundant number, since it is smaller than the sum of its proper divisors (38901413512615).

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

27991209489800 is an frugal number, since it uses more digits than its factorization.

27991209489800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20312 (or 10155 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 68.

The spelling of 27991209489800 in words is "twenty-seven trillion, nine hundred ninety-one billion, two hundred nine million, four hundred eighty-nine thousand, eight hundred".