27991200 has 144 divisors (see below), whose sum is σ = 92806560. Its totient is φ = 7326720.

The previous prime is 27991157. The next prime is 27991213. The reversal of 27991200 is 219972.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 256746 + ... + 256854.

It is an arithmetic number, because the mean of its divisors is an integer number (644490).

Almost surely, 2^27991200 is an apocalyptic number.

27991200 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 27991200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46403280).

27991200 is an abundant number, since it is smaller than the sum of its proper divisors (64815360).

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

27991200 is a wasteful number, since it uses less digits than its factorization.

27991200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 30.

The square root of 27991200 is about 5290.6710349444. The cubic root of 27991200 is about 303.6270819698.

The spelling of 27991200 in words is "twenty-seven million, nine hundred ninety-one thousand, two hundred".