4206721 has 2 divisors, whose sum is σ = 4206722. Its totient is φ = 4206720.

The previous prime is 4206703. The next prime is 4206737. The reversal of 4206721 is 1276024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3330625 + 876096 = 1825^2 + 936^2 .

It is a cyclic number.

It is not a de Polignac number, because 4206721 - 2⁷ = 4206593 is a prime.

It is a super-3 number, since 3×4206721³ (a number of 21 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 4206692 and 4206701.

It is not a weakly prime, because it can be changed into another prime (4206781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2103360 + 2103361.

It is an arithmetic number, because the mean of its divisors is an integer number (2103361).

Almost surely, 2^4206721 is an apocalyptic number.

It is an amenable number.

4206721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4206721 is an equidigital number, since it uses as much as digits as its factorization.

4206721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 4206721 is about 2051.0292538138. The cubic root of 4206721 is about 161.4288810693.

The spelling of 4206721 in words is "four million, two hundred six thousand, seven hundred twenty-one".