222121 has 4 divisors (see below), whose sum is σ = 223744. Its totient is φ = 220500.

The previous prime is 222113. The next prime is 222127. The reversal of 222121 is 121222.

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, and also an emirpimes, since its reverse is a distinct semiprime: 121222 = 2 ⋅60611.

It is a cyclic number.

It is not a de Polignac number, because 222121 - 2³ = 222113 is a prime.

It is a Duffinian number.

222121 is a lucky number.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 222098 and 222107.

It is not an unprimeable number, because it can be changed into a prime (222127) 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, 585 + ... + 886.

It is an arithmetic number, because the mean of its divisors is an integer number (55936).

2²²²¹²¹ is an apocalyptic number.

It is an amenable number.

222121 is a deficient number, since it is larger than the sum of its proper divisors (1623).

222121 is a wasteful number, since it uses less digits than its factorization.

222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622.

The product of its digits is 16, while the sum is 10.

The square root of 222121 is about 471.2971461827. The cubic root of 222121 is about 60.5614883818.

Subtracting from 222121 its sum of digits (10), we obtain a triangular number (222111 = T₆₆₆).

Adding to 222121 its reverse (121222), we get a palindrome (343343).

It can be divided in two parts, 222 and 121, that multiplied together give a palindrome (26862).

The spelling of 222121 in words is "two hundred twenty-two thousand, one hundred twenty-one", and thus it is an iban number.