4216721 has 2 divisors, whose sum is σ = 4216722. Its totient is φ = 4216720.

The previous prime is 4216691. The next prime is 4216741. The reversal of 4216721 is 1276124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2356225 + 1860496 = 1535^2 + 1364^2 .

It is a cyclic number.

It is not a de Polignac number, because 4216721 - 2⁶ = 4216657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (4216741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2108360 + 2108361.

It is an arithmetic number, because the mean of its divisors is an integer number (2108361).

Almost surely, 2^4216721 is an apocalyptic number.

It is an amenable number.

4216721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4216721 is an equidigital number, since it uses as much as digits as its factorization.

4216721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 23.

The square root of 4216721 is about 2053.4656072114. The cubic root of 4216721 is about 161.5566933140.

The spelling of 4216721 in words is "four million, two hundred sixteen thousand, seven hundred twenty-one".