1278538154916 has 96 divisors (see below), whose sum is σ = 3352521338880. Its totient is φ = 375825225600.

The previous prime is 1278538154899. The next prime is 1278538155029. The reversal of 1278538154916 is 6194518358721.

It is a happy number.

It is a super-2 number, since 2×1278538154916² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1278538154916.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1221165 + ... + 2012043.

It is an arithmetic number, because the mean of its divisors is an integer number (34922097280).

Almost surely, 2^{1278538154916} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278538154916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1676260669440).

1278538154916 is an abundant number, since it is smaller than the sum of its proper divisors (2073983183964).

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

1278538154916 is a wasteful number, since it uses less digits than its factorization.

1278538154916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791265 (or 791263 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 60.

The spelling of 1278538154916 in words is "one trillion, two hundred seventy-eight billion, five hundred thirty-eight million, one hundred fifty-four thousand, nine hundred sixteen".