1278725616 has 200 divisors, whose sum is σ = 4321152000. Its totient is φ = 357457536.

The previous prime is 1278725611. The next prime is 1278725627. The reversal of 1278725616 is 6165278721.

1278725616 is a `hidden beast` number, since 1 + 2 + 7 + 8 + 7 + 25 + 616 = 666.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278725611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 424885 + ... + 427883.

It is an arithmetic number, because the mean of its divisors is an integer number (21605760).

Almost surely, 2^1278725616 is an apocalyptic number.

1278725616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278725616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2160576000).

1278725616 is an abundant number, since it is smaller than the sum of its proper divisors (3042426384).

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

1278725616 is a wasteful number, since it uses less digits than its factorization.

1278725616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073 (or 3058 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 1278725616 is about 35759.2731469755. The cubic root of 1278725616 is about 1085.4065925727.

The spelling of 1278725616 in words is "one billion, two hundred seventy-eight million, seven hundred twenty-five thousand, six hundred sixteen".