210121 has 4 divisors (see below), whose sum is σ = 221200. Its totient is φ = 199044.

The previous prime is 210113. The next prime is 210127. The reversal of 210121 is 121012.

210121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

210121 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 not a de Polignac number, because 210121 - 2³ = 210113 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210127) 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, 5511 + ... + 5548.

It is an arithmetic number, because the mean of its divisors is an integer number (55300).

2²¹⁰¹²¹ is an apocalyptic number.

It is an amenable number.

210121 is a deficient number, since it is larger than the sum of its proper divisors (11079).

210121 is a wasteful number, since it uses less digits than its factorization.

210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11078.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 210121 is about 458.3895723072. The cubic root of 210121 is about 59.4506334398.

Adding to 210121 its reverse (121012), we get a palindrome (331133).

The spelling of 210121 in words is "two hundred ten thousand, one hundred twenty-one", and thus it is an iban number.