4222721 has 2 divisors, whose sum is σ = 4222722. Its totient is φ = 4222720.

The previous prime is 4222717. The next prime is 4222723. The reversal of 4222721 is 1272224.

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., 3474496 + 748225 = 1864^2 + 865^2 .

It is a cyclic number.

It is not a de Polignac number, because 4222721 - 2² = 4222717 is a prime.

Together with 4222723, 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 = 4222693 and 4222702.

It is not a weakly prime, because it can be changed into another prime (4222723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2111360 + 2111361.

It is an arithmetic number, because the mean of its divisors is an integer number (2111361).

Almost surely, 2^4222721 is an apocalyptic number.

It is an amenable number.

4222721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4222721 is an equidigital number, since it uses as much as digits as its factorization.

4222721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 448, while the sum is 20.

The square root of 4222721 is about 2054.9260327321. The cubic root of 4222721 is about 161.6332836918.

Adding to 4222721 its reverse (1272224), we get a palindrome (5494945).

The spelling of 4222721 in words is "four million, two hundred twenty-two thousand, seven hundred twenty-one".