12131778 has 32 divisors (see below), whose sum is σ = 26018496. Its totient is φ = 3757568.

The previous prime is 12131771. The next prime is 12131789. The reversal of 12131778 is 87713121.

12131778 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 Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12131771) 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, 7750 + ... + 9182.

It is an arithmetic number, because the mean of its divisors is an integer number (813078).

Almost surely, 2^12131778 is an apocalyptic number.

12131778 is an abundant number, since it is smaller than the sum of its proper divisors (13886718).

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

12131778 is a wasteful number, since it uses less digits than its factorization.

12131778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1538.

The product of its digits is 2352, while the sum is 30.

The square root of 12131778 is about 3483.0701973977. The cubic root of 12131778 is about 229.7778447222. Note that the first 3 decimals are identical.

Adding to 12131778 its reverse (87713121), we get a palindrome (99844899).

The spelling of 12131778 in words is "twelve million, one hundred thirty-one thousand, seven hundred seventy-eight".