3121221 has 4 divisors (see below), whose sum is σ = 4161632. Its totient is φ = 2080812.

The previous prime is 3121219. The next prime is 3121229. The reversal of 3121221 is 1221213.

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 3121221 - 2¹ = 3121219 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 3121197 and 3121206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3121229) 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, 520201 + ... + 520206.

It is an arithmetic number, because the mean of its divisors is an integer number (1040408).

Almost surely, 2^3121221 is an apocalyptic number.

It is an amenable number.

3121221 is a deficient number, since it is larger than the sum of its proper divisors (1040411).

3121221 is a wasteful number, since it uses less digits than its factorization.

3121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040410.

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

The square root of 3121221 is about 1766.6977670219. The cubic root of 3121221 is about 146.1419305365.

Adding to 3121221 its reverse (1221213), we get a palindrome (4342434).

The spelling of 3121221 in words is "three million, one hundred twenty-one thousand, two hundred twenty-one".