1278528221440 has 72 divisors (see below), whose sum is σ = 3112679322648. Its totient is φ = 503027466240.

The previous prime is 1278528221419. The next prime is 1278528221447. The reversal of 1278528221440 is 441228258721.

It can be written as a sum of positive squares in 4 ways, for example, as 7010377984 + 1271517843456 = 83728^2 + 1127616^2 .

It is not an unprimeable number, because it can be changed into a prime (1278528221447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8109217 + ... + 8265376.

It is an arithmetic number, because the mean of its divisors is an integer number (43231657259).

Almost surely, 2^{1278528221440} is an apocalyptic number.

1278528221440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1278528221440 is an abundant number, since it is smaller than the sum of its proper divisors (1834151101208).

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

1278528221440 is an equidigital number, since it uses as much as digits as its factorization.

1278528221440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16374675 (or 16374661 counting only the distinct ones).

The product of its (nonzero) digits is 573440, while the sum is 46.

The spelling of 1278528221440 in words is "one trillion, two hundred seventy-eight billion, five hundred twenty-eight million, two hundred twenty-one thousand, four hundred forty".