2131221 has 8 divisors (see below), whose sum is σ = 2911104. Its totient is φ = 1386080.

The previous prime is 2131193. The next prime is 2131223. The reversal of 2131221 is 1221312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2131221 - 2⁷ = 2131093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2131197 and 2131206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131223) 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 in 7 ways as a sum of consecutive naturals, for example, 8541 + ... + 8786.

It is an arithmetic number, because the mean of its divisors is an integer number (363888).

2^2131221 is an apocalyptic number.

It is an amenable number.

2131221 is a deficient number, since it is larger than the sum of its proper divisors (779883).

2131221 is a wasteful number, since it uses less digits than its factorization.

2131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17371.

The product of its digits is 24, while the sum is 12.

The square root of 2131221 is about 1459.8701997095. The cubic root of 2131221 is about 128.6894156787.

Adding to 2131221 its reverse (1221312), we get a palindrome (3352533).

Subtracting from 2131221 its reverse (1221312), we obtain a palindrome (909909).

The spelling of 2131221 in words is "two million, one hundred thirty-one thousand, two hundred twenty-one".