1278761329872 has 720 divisors, whose sum is σ = 4253660784000. Its totient is φ = 372134041344.

The previous prime is 1278761329871. The next prime is 1278761329873. The reversal of 1278761329872 is 2789231678721.

1278761329872 is a `hidden beast` number, since 1 + 2 + 7 + 8 + 7 + 613 + 2 + 9 + 8 + 7 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (1278761329871) and next prime (1278761329873).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278761329871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2134826629 + ... + 2134827227.

It is an arithmetic number, because the mean of its divisors is an integer number (5907862200).

Almost surely, 2^{1278761329872} is an apocalyptic number.

1278761329872 is a gapful number since it is divisible by the number (12) 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 1278761329872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2126830392000).

1278761329872 is an abundant number, since it is smaller than the sum of its proper divisors (2974899454128).

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

1278761329872 is an equidigital number, since it uses as much as digits as its factorization.

1278761329872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692 (or 636 counting only the distinct ones).

The product of its digits is 28449792, while the sum is 63.

The spelling of 1278761329872 in words is "one trillion, two hundred seventy-eight billion, seven hundred sixty-one million, three hundred twenty-nine thousand, eight hundred seventy-two".