231620 has 24 divisors (see below), whose sum is σ = 501144. Its totient is φ = 89856.

The previous prime is 231613. The next prime is 231631. The reversal of 231620 is 26132.

It can be written as a sum of positive squares in 4 ways, for example, as 8836 + 222784 = 94^2 + 472^2 .

It is a junction number, because it is equal to n+sod(n) for n = 231595 and 231604.

It is an unprimeable number.

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, 584 + ... + 896.

It is an arithmetic number, because the mean of its divisors is an integer number (20881).

2²³¹⁶²⁰ is an apocalyptic number.

231620 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 231620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250572).

231620 is an abundant number, since it is smaller than the sum of its proper divisors (269524).

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

231620 is a wasteful number, since it uses less digits than its factorization.

231620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 231620 is about 481.2691554629. The cubic root of 231620 is about 61.4127698933.

Adding to 231620 its reverse (26132), we get a palindrome (257752).

The spelling of 231620 in words is "two hundred thirty-one thousand, six hundred twenty".