828717220121 has 6 divisors (see below), whose sum is σ = 964017990810. Its totient is φ = 710329045776.

The previous prime is 828717220069. The next prime is 828717220147. The reversal of 828717220121 is 121022717828.

It can be written as a sum of positive squares in only one way, i.e., 662302992400 + 166414227721 = 813820^2 + 407939^2 .

It is a de Polignac number, because none of the positive numbers 2^k-828717220121 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (828717220171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8456298116 + ... + 8456298213.

It is an arithmetic number, because the mean of its divisors is an integer number (160669665135).

Almost surely, 2^828717220121 is an apocalyptic number.

It is an amenable number.

828717220121 is a deficient number, since it is larger than the sum of its proper divisors (135300770689).

828717220121 is a wasteful number, since it uses less digits than its factorization.

828717220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16912596343 (or 16912596336 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 41.

Adding to 828717220121 its reverse (121022717828), we get a palindrome (949739937949).

The spelling of 828717220121 in words is "eight hundred twenty-eight billion, seven hundred seventeen million, two hundred twenty thousand, one hundred twenty-one".