12778381 has 16 divisors (see below), whose sum is σ = 16017408. Its totient is φ = 9903600.

The previous prime is 12778369. The next prime is 12778391. The reversal of 12778381 is 18387721.

12778381 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 12778381 - 2⁷ = 12778253 is a prime.

It is a super-2 number, since 2×12778381² = 326574041962322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12778381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12778331) 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, 19936 + ... + 20566.

It is an arithmetic number, because the mean of its divisors is an integer number (1001088).

Almost surely, 2^12778381 is an apocalyptic number.

12778381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12778381 is a deficient number, since it is larger than the sum of its proper divisors (3239027).

12778381 is a wasteful number, since it uses less digits than its factorization.

12778381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912.

The product of its digits is 18816, while the sum is 37.

The square root of 12778381 is about 3574.6861400688. The cubic root of 12778381 is about 233.7896483023.

The spelling of 12778381 in words is "twelve million, seven hundred seventy-eight thousand, three hundred eighty-one".