331621 has 4 divisors (see below), whose sum is σ = 337932. Its totient is φ = 325312.

The previous prime is 331613. The next prime is 331651. The reversal of 331621 is 126133.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 297025 + 34596 = 545^2 + 186^2 .

It is a cyclic number.

It is not a de Polignac number, because 331621 - 2³ = 331613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 331595 and 331604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3076 + ... + 3181.

It is an arithmetic number, because the mean of its divisors is an integer number (84483).

2³³¹⁶²¹ is an apocalyptic number.

It is an amenable number.

331621 is a deficient number, since it is larger than the sum of its proper divisors (6311).

331621 is an equidigital number, since it uses as much as digits as its factorization.

331621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6310.

The product of its digits is 108, while the sum is 16.

The square root of 331621 is about 575.8654356705. The cubic root of 331621 is about 69.2171969912.

Adding to 331621 its reverse (126133), we get a palindrome (457754).

The spelling of 331621 in words is "three hundred thirty-one thousand, six hundred twenty-one".