421613221 has 2 divisors, whose sum is σ = 421613222. Its totient is φ = 421613220.

The previous prime is 421613219. The next prime is 421613239. The reversal of 421613221 is 122316124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 361380100 + 60233121 = 19010^2 + 7761^2 .

It is a cyclic number.

It is not a de Polignac number, because 421613221 - 2¹ = 421613219 is a prime.

Together with 421613219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 421613192 and 421613201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421613201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210806610 + 210806611.

It is an arithmetic number, because the mean of its divisors is an integer number (210806611).

Almost surely, 2^421613221 is an apocalyptic number.

It is an amenable number.

421613221 is a deficient number, since it is larger than the sum of its proper divisors (1).

421613221 is an equidigital number, since it uses as much as digits as its factorization.

421613221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 22.

The square root of 421613221 is about 20533.2223725357. Note that the first 3 decimals coincide. The cubic root of 421613221 is about 749.8448396063.

Adding to 421613221 its reverse (122316124), we get a palindrome (543929345).

The spelling of 421613221 in words is "four hundred twenty-one million, six hundred thirteen thousand, two hundred twenty-one".