828170981521 has 9 divisors (see below), whose sum is σ = 896789672379. Its totient is φ = 764454600936.

The previous prime is 828170981509. The next prime is 828170981569. The reversal of 828170981521 is 125189071828.

The square root of 828170981521 is 910039.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 122510500225 + 705660481296 = 350015^2 + 840036^2 .

It is not a de Polignac number, because 828170981521 - 2⁵ = 828170981489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (828170982521) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11795506 + ... + 11865508.

It is an arithmetic number, because the mean of its divisors is an integer number (99643296931).

Almost surely, 2^828170981521 is an apocalyptic number.

828170981521 is the 910039-th square number.

828170981521 is the 455020-th centered octagonal number.

It is an amenable number.

828170981521 is a deficient number, since it is larger than the sum of its proper divisors (68618690858).

828170981521 is an frugal number, since it uses more digits than its factorization.

828170981521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140032 (or 70016 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 52.

The spelling of 828170981521 in words is "eight hundred twenty-eight billion, one hundred seventy million, nine hundred eighty-one thousand, five hundred twenty-one".