12129778 has 8 divisors (see below), whose sum is σ = 18209772. Its totient is φ = 6059856.

The previous prime is 12129769. The next prime is 12129781. The reversal of 12129778 is 87792121.

It can be written as a sum of positive squares in 2 ways, for example, as 11950849 + 178929 = 3457^2 + 423^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2476 + ... + 5512.

Almost surely, 2^12129778 is an apocalyptic number.

12129778 is a deficient number, since it is larger than the sum of its proper divisors (6079994).

12129778 is a wasteful number, since it uses less digits than its factorization.

12129778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5036.

The product of its digits is 14112, while the sum is 37.

The square root of 12129778 is about 3482.7830825361. The cubic root of 12129778 is about 229.7652172534.

The spelling of 12129778 in words is "twelve million, one hundred twenty-nine thousand, seven hundred seventy-eight".