27991600 has 120 divisors (see below), whose sum is σ = 82876640. Its totient is φ = 8847360.

The previous prime is 27991577. The next prime is 27991603. The reversal of 27991600 is 619972.

It is not an unprimeable number, because it can be changed into a prime (27991603) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36016 + ... + 36784.

Almost surely, 2^27991600 is an apocalyptic number.

27991600 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 27991600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41438320).

27991600 is an abundant number, since it is smaller than the sum of its proper divisors (54885040).

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

27991600 is a wasteful number, since it uses less digits than its factorization.

27991600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 807 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 27991600 is about 5290.7088371975. The cubic root of 27991600 is about 303.6285282608.

The spelling of 27991600 in words is "twenty-seven million, nine hundred ninety-one thousand, six hundred".