3128781256285 has 16 divisors (see below), whose sum is σ = 3755857664880. Its totient is φ = 2502145105920.

The previous prime is 3128781256259. The next prime is 3128781256339. The reversal of 3128781256285 is 5826521878213.

It can be written as a sum of positive squares in 8 ways, for example, as 293393388964 + 2835387867321 = 541658^2 + 1683861^2 .

It is not a de Polignac number, because 3128781256285 - 2¹⁹ = 3128780731997 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 331679929 + ... + 331689361.

It is an arithmetic number, because the mean of its divisors is an integer number (234741104055).

Almost surely, 2^{3128781256285} is an apocalyptic number.

It is an amenable number.

3128781256285 is a deficient number, since it is larger than the sum of its proper divisors (627076408595).

3128781256285 is an equidigital number, since it uses as much as digits as its factorization.

3128781256285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25728.

The product of its digits is 12902400, while the sum is 58.

The spelling of 3128781256285 in words is "three trillion, one hundred twenty-eight billion, seven hundred eighty-one million, two hundred fifty-six thousand, two hundred eighty-five".