11981880 has 96 divisors (see below), whose sum is σ = 39508560. Its totient is φ = 3148800.

The previous prime is 11981867. The next prime is 11981891. The reversal of 11981880 is 8818911.

11981880 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29680 + ... + 30080.

Almost surely, 2^11981880 is an apocalyptic number.

11981880 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 11981880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19754280).

11981880 is an abundant number, since it is smaller than the sum of its proper divisors (27526680).

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

11981880 is a wasteful number, since it uses less digits than its factorization.

11981880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 494 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 11981880 is about 3461.4852303599. The cubic root of 11981880 is about 228.8275558935.

The spelling of 11981880 in words is "eleven million, nine hundred eighty-one thousand, eight hundred eighty".