2221006421 has 2 divisors, whose sum is σ = 2221006422. Its totient is φ = 2221006420.

The previous prime is 2221006397. The next prime is 2221006423. The reversal of 2221006421 is 1246001222.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1476480625 + 744525796 = 38425^2 + 27286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2221006421 is a prime.

Together with 2221006423, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 2221006393 and 2221006402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221006423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110503210 + 1110503211.

It is an arithmetic number, because the mean of its divisors is an integer number (1110503211).

Almost surely, 2^2221006421 is an apocalyptic number.

It is an amenable number.

2221006421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221006421 is an equidigital number, since it uses as much as digits as its factorization.

2221006421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 2221006421 is about 47127.5547954697. The cubic root of 2221006421 is about 1304.7178519319.

Adding to 2221006421 its reverse (1246001222), we get a palindrome (3467007643).

The spelling of 2221006421 in words is "two billion, two hundred twenty-one million, six thousand, four hundred twenty-one".