128251878722 has 18 divisors (see below), whose sum is σ = 211465795737. Its totient is φ = 58293776200.

The previous prime is 128251878721. The next prime is 128251878731. The reversal of 128251878722 is 227878152821.

It can be written as a sum of positive squares in 2 ways, for example, as 106941426361 + 21310452361 = 327019^2 + 145981^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=253231.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128251878721) 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 8 ways as a sum of consecutive naturals, for example, 5559572 + ... + 5582592.

Almost surely, 2^128251878722 is an apocalyptic number.

128251878722 is a deficient number, since it is larger than the sum of its proper divisors (83213917015).

128251878722 is an frugal number, since it uses more digits than its factorization.

128251878722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46066 (or 23034 counting only the distinct ones).

The product of its digits is 2007040, while the sum is 53.

The spelling of 128251878722 in words is "one hundred twenty-eight billion, two hundred fifty-one million, eight hundred seventy-eight thousand, seven hundred twenty-two".