256821128652 has 192 divisors, whose sum is σ = 718930598400. Its totient is φ = 70479360000.

The previous prime is 256821128609. The next prime is 256821128699.

256821128652 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7328452 + ... + 7363412.

It is an arithmetic number, because the mean of its divisors is an integer number (3744430200).

Almost surely, 2^256821128652 is an apocalyptic number.

256821128652 is a gapful number since it is divisible by the number (22) 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 256821128652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (359465299200).

256821128652 is an abundant number, since it is smaller than the sum of its proper divisors (462109469748).

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

256821128652 is a wasteful number, since it uses less digits than its factorization.

256821128652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35128 (or 35126 counting only the distinct ones).

The product of its digits is 921600, while the sum is 48.

The spelling of 256821128652 in words is "two hundred fifty-six billion, eight hundred twenty-one million, one hundred twenty-eight thousand, six hundred fifty-two".