11783981 has 16 divisors (see below), whose sum is σ = 13713408. Its totient is φ = 10018800.

The previous prime is 11783969. The next prime is 11783987. The reversal of 11783981 is 18938711.

11783981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11783981 - 2⁶ = 11783917 is a prime.

It is a super-2 number, since 2×11783981² = 277724416416722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11783987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11396 + ... + 12386.

It is an arithmetic number, because the mean of its divisors is an integer number (857088).

Almost surely, 2^11783981 is an apocalyptic number.

11783981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11783981 is a deficient number, since it is larger than the sum of its proper divisors (1929427).

11783981 is a wasteful number, since it uses less digits than its factorization.

11783981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072.

The product of its digits is 12096, while the sum is 38.

The square root of 11783981 is about 3432.7803599997. The cubic root of 11783981 is about 227.5607437523.

The spelling of 11783981 in words is "eleven million, seven hundred eighty-three thousand, nine hundred eighty-one".