123621 has 8 divisors (see below), whose sum is σ = 167040. Its totient is φ = 81312.

The previous prime is 123619. The next prime is 123631. The reversal of 123621 is 126321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123621 - 2¹ = 123619 is a prime.

123621 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 123621.

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 123621.

It is not an unprimeable number, because it can be changed into a prime (123601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36 + ... + 498.

It is an arithmetic number, because the mean of its divisors is an integer number (20880).

2¹²³⁶²¹ is an apocalyptic number.

It is an amenable number.

123621 is a deficient number, since it is larger than the sum of its proper divisors (43419).

123621 is an equidigital number, since it uses as much as digits as its factorization.

123621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555.

The product of its digits is 72, while the sum is 15.

The square root of 123621 is about 351.5977815630. The cubic root of 123621 is about 49.8154530196.

Adding to 123621 its reverse (126321), we get a palindrome (249942).

The spelling of 123621 in words is "one hundred twenty-three thousand, six hundred twenty-one".