221232121 has 16 divisors (see below), whose sum is σ = 246558528. Its totient is φ = 196819200.

The previous prime is 221232113. The next prime is 221232127. The reversal of 221232121 is 121232122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221232121 - 2³ = 221232113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221232095 and 221232104.

It is not an unprimeable number, because it can be changed into a prime (221232127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109006 + ... + 111016.

It is an arithmetic number, because the mean of its divisors is an integer number (15409908).

Almost surely, 2^221232121 is an apocalyptic number.

It is an amenable number.

221232121 is a deficient number, since it is larger than the sum of its proper divisors (25326407).

221232121 is a wasteful number, since it uses less digits than its factorization.

221232121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232.

The product of its digits is 96, while the sum is 16.

The square root of 221232121 is about 14873.8737724911. The cubic root of 221232121 is about 604.8059583076.

Adding to 221232121 its reverse (121232122), we get a palindrome (342464243).

Subtracting from 221232121 its reverse (121232122), we obtain a palindrome (99999999).

The spelling of 221232121 in words is "two hundred twenty-one million, two hundred thirty-two thousand, one hundred twenty-one".