831906343921 has 3 divisors (see below), whose sum is σ = 831907256011. Its totient is φ = 831905431832.

The previous prime is 831906343909. The next prime is 831906343949. The reversal of 831906343921 is 129343609138.

The square root of 831906343921 is 912089.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 831672865521 + 233478400 = 911961^2 + 15280^2 .

It is not a de Polignac number, because 831906343921 - 2²⁹ = 831369473009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (831906343901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 456045 + ... + 1368133.

Almost surely, 2^831906343921 is an apocalyptic number.

831906343921 is the 912089-th square number.

831906343921 is the 456045-th centered octagonal number.

It is an amenable number.

831906343921 is a deficient number, since it is larger than the sum of its proper divisors (912090).

831906343921 is an frugal number, since it uses more digits than its factorization.

831906343921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1824178 (or 912089 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 49.

Multiplying 831906343921 by its sum of digits (49), we get a square (40763410852129 = 6384623²).

The spelling of 831906343921 in words is "eight hundred thirty-one billion, nine hundred six million, three hundred forty-three thousand, nine hundred twenty-one".