11981800 has 48 divisors (see below), whose sum is σ = 28123200. Its totient is φ = 4747200.

The previous prime is 11981791. The next prime is 11981813. The reversal of 11981800 is 818911.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27585 + ... + 28015.

It is an arithmetic number, because the mean of its divisors is an integer number (585900).

Almost surely, 2^11981800 is an apocalyptic number.

11981800 is a gapful number since it is divisible by the number (10) 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 11981800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14061600).

11981800 is an abundant number, since it is smaller than the sum of its proper divisors (16141400).

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

11981800 is a wasteful number, since it uses less digits than its factorization.

11981800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 11981800 is about 3461.4736746074. The cubic root of 11981800 is about 228.8270466177.

The spelling of 11981800 in words is "eleven million, nine hundred eighty-one thousand, eight hundred".