2221236421 has 4 divisors (see below), whose sum is σ = 2232745612. Its totient is φ = 2209727232.

The previous prime is 2221236419. The next prime is 2221236467. The reversal of 2221236421 is 1246321222.

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 408605796 + 1812630625 = 20214^2 + 42575^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221236421 - 2¹ = 2221236419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221246421) 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, 5754306 + ... + 5754691.

It is an arithmetic number, because the mean of its divisors is an integer number (558186403).

Almost surely, 2^2221236421 is an apocalyptic number.

It is an amenable number.

2221236421 is a deficient number, since it is larger than the sum of its proper divisors (11509191).

2221236421 is a wasteful number, since it uses less digits than its factorization.

2221236421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11509190.

The product of its digits is 2304, while the sum is 25.

The square root of 2221236421 is about 47129.9949183108. The cubic root of 2221236421 is about 1304.7628877837.

Adding to 2221236421 its reverse (1246321222), we get a palindrome (3467557643).

The spelling of 2221236421 in words is "two billion, two hundred twenty-one million, two hundred thirty-six thousand, four hundred twenty-one".