100621 has 2 divisors, whose sum is σ = 100622. Its totient is φ = 100620.

The previous prime is 100613. The next prime is 100649. The reversal of 100621 is 126001.

It is the 130-th star number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98596 + 2025 = 314^2 + 45^2 .

It is an emirp because it is prime and its reverse (126001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100621 - 2³ = 100613 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 100598 and 100607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (106621) 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 as a sum of consecutive naturals, namely, 50310 + 50311.

It is an arithmetic number, because the mean of its divisors is an integer number (50311).

2¹⁰⁰⁶²¹ is an apocalyptic number.

It is an amenable number.

100621 is a deficient number, since it is larger than the sum of its proper divisors (1).

100621 is an equidigital number, since it uses as much as digits as its factorization.

100621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 100621 is about 317.2081335653. The cubic root of 100621 is about 46.5117710209.

Adding to 100621 its reverse (126001), we get a palindrome (226622).

The spelling of 100621 in words is "one hundred thousand, six hundred twenty-one".