2221421 has 4 divisors (see below), whose sum is σ = 2275644. Its totient is φ = 2167200.

The previous prime is 2221411. The next prime is 2221433. The reversal of 2221421 is 1241222.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45796 + 2175625 = 214^2 + 1475^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2221421 is a prime.

It is a super-2 number, since 2×2221421² = 9869422518482, which contains 22 as substring.

It is an Ulam 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 = 2221396 and 2221405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221411) 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, 27050 + ... + 27131.

It is an arithmetic number, because the mean of its divisors is an integer number (568911).

2^2221421 is an apocalyptic number.

It is an amenable number.

2221421 is a deficient number, since it is larger than the sum of its proper divisors (54223).

2221421 is an equidigital number, since it uses as much as digits as its factorization.

2221421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54222.

The product of its digits is 64, while the sum is 14.

The square root of 2221421 is about 1490.4432226690. The cubic root of 2221421 is about 130.4799027589.

Adding to 2221421 its reverse (1241222), we get a palindrome (3462643).

The spelling of 2221421 in words is "two million, two hundred twenty-one thousand, four hundred twenty-one".