4056721 has 2 divisors, whose sum is σ = 4056722. Its totient is φ = 4056720.

The previous prime is 4056719. The next prime is 4056733. The reversal of 4056721 is 1276504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2822400 + 1234321 = 1680^2 + 1111^2 .

It is a cyclic number.

It is not a de Polignac number, because 4056721 - 2¹ = 4056719 is a prime.

Together with 4056719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (4056751) 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, 2028360 + 2028361.

It is an arithmetic number, because the mean of its divisors is an integer number (2028361).

Almost surely, 2^4056721 is an apocalyptic number.

It is an amenable number.

4056721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4056721 is an equidigital number, since it uses as much as digits as its factorization.

4056721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 4056721 is about 2014.1303334194. The cubic root of 4056721 is about 159.4869110697.

The spelling of 4056721 in words is "four million, fifty-six thousand, seven hundred twenty-one".