831211920 has 720 divisors, whose sum is σ = 3704762880. Its totient is φ = 163215360.

The previous prime is 831211907. The next prime is 831211933. The reversal of 831211920 is 29112138.

It is an interprime number because it is at equal distance from previous prime (831211907) and next prime (831211933).

It is a tau number, because it is divible by the number of its divisors (720).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 17685337 + ... + 17685383.

It is an arithmetic number, because the mean of its divisors is an integer number (5145504).

Almost surely, 2^831211920 is an apocalyptic number.

831211920 is a gapful number since it is divisible by the number (80) 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 831211920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1852381440).

831211920 is an abundant number, since it is smaller than the sum of its proper divisors (2873550960).

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

831211920 is a wasteful number, since it uses less digits than its factorization.

831211920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 831211920 is about 28830.7460881608. The cubic root of 831211920 is about 940.2368197642.

The spelling of 831211920 in words is "eight hundred thirty-one million, two hundred eleven thousand, nine hundred twenty".