820939830717 has 16 divisors (see below), whose sum is σ = 1110040474752. Its totient is φ = 539566722240.

The previous prime is 820939830661. The next prime is 820939830719. The reversal of 820939830717 is 717038939028.

It is not a de Polignac number, because 820939830717 - 2⁶ = 820939830653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820939830719) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9806803 + ... + 9890159.

It is an arithmetic number, because the mean of its divisors is an integer number (69377529672).

Almost surely, 2^820939830717 is an apocalyptic number.

It is an amenable number.

820939830717 is a deficient number, since it is larger than the sum of its proper divisors (289100644035).

820939830717 is a wasteful number, since it uses less digits than its factorization.

820939830717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129668.

The product of its (nonzero) digits is 4572288, while the sum is 57.

The spelling of 820939830717 in words is "eight hundred twenty billion, nine hundred thirty-nine million, eight hundred thirty thousand, seven hundred seventeen".