291920 has 40 divisors (see below), whose sum is σ = 703080. Its totient is φ = 112640.

The previous prime is 291901. The next prime is 291923. The reversal of 291920 is 29192.

It can be written as a sum of positive squares in 4 ways, for example, as 4624 + 287296 = 68^2 + 536^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291920.

It is not an unprimeable number, because it can be changed into a prime (291923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3236 + ... + 3324.

It is an arithmetic number, because the mean of its divisors is an integer number (17577).

2²⁹¹⁹²⁰ is an apocalyptic number.

291920 is a gapful number since it is divisible by the number (20) 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 291920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351540).

291920 is an abundant number, since it is smaller than the sum of its proper divisors (411160).

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

291920 is a wasteful number, since it uses less digits than its factorization.

291920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 291920 is about 540.2962150524. The cubic root of 291920 is about 66.3368151053.

The spelling of 291920 in words is "two hundred ninety-one thousand, nine hundred twenty".