1398778872128 has 84 divisors (see below), whose sum is σ = 3051465833556. Its totient is φ = 635706931200.

The previous prime is 1398778872121. The next prime is 1398778872157. The reversal of 1398778872128 is 8212788778931.

It can be written as a sum of positive squares in 2 ways, for example, as 247295354944 + 1151483517184 = 497288^2 + 1073072^2 .

It is a super-2 number, since 2×1398778872128² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398778872121) 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 11 ways as a sum of consecutive naturals, for example, 70932926 + ... + 70952642.

It is an arithmetic number, because the mean of its divisors is an integer number (36326974209).

Almost surely, 2^{1398778872128} 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 1398778872128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1525732916778).

1398778872128 is an abundant number, since it is smaller than the sum of its proper divisors (1652686961428).

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

1398778872128 is a wasteful number, since it uses less digits than its factorization.

1398778872128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28912 (or 28891 counting only the distinct ones).

The product of its digits is 151732224, while the sum is 71.

The spelling of 1398778872128 in words is "one trillion, three hundred ninety-eight billion, seven hundred seventy-eight million, eight hundred seventy-two thousand, one hundred twenty-eight".