100121 has 4 divisors (see below), whose sum is σ = 114432. Its totient is φ = 85812.

The previous prime is 100109. The next prime is 100129. The reversal of 100121 is 121001.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 100121 - 2⁶ = 100057 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100129) 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, 7145 + ... + 7158.

It is an arithmetic number, because the mean of its divisors is an integer number (28608).

2¹⁰⁰¹²¹ is an apocalyptic number.

It is an amenable number.

100121 is a deficient number, since it is larger than the sum of its proper divisors (14311).

100121 is an equidigital number, since it uses as much as digits as its factorization.

100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14310.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 100121 is about 316.4190259766. The cubic root of 100121 is about 46.4346018653.

Adding to 100121 its reverse (121001), we get a palindrome (221122).

Multiplying 100121 by its reverse (121001), we get a palindrome (12114741121).

It can be divided in two parts, 100 and 121, that multiplied together give a square (12100 = 110²).

The spelling of 100121 in words is "one hundred thousand, one hundred twenty-one", and thus it is an iban number.