12778389 has 24 divisors (see below), whose sum is σ = 20038200. Its totient is φ = 7800192.

The previous prime is 12778369. The next prime is 12778391. The reversal of 12778389 is 98387721.

It can be written as a sum of positive squares in 4 ways, for example, as 1102500 + 11675889 = 1050^2 + 3417^2 .

It is not a de Polignac number, because 12778389 - 2¹⁷ = 12647317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12778309) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17067 + ... + 17799.

It is an arithmetic number, because the mean of its divisors is an integer number (834925).

Almost surely, 2^12778389 is an apocalyptic number.

It is an amenable number.

12778389 is a deficient number, since it is larger than the sum of its proper divisors (7259811).

12778389 is a wasteful number, since it uses less digits than its factorization.

12778389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901 (or 898 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 12778389 is about 3574.6872590480. The cubic root of 12778389 is about 233.7896970909.

The spelling of 12778389 in words is "twelve million, seven hundred seventy-eight thousand, three hundred eighty-nine".