6432721 has 2 divisors, whose sum is σ = 6432722. Its totient is φ = 6432720.

The previous prime is 6432707. The next prime is 6432739. The reversal of 6432721 is 1272346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5198400 + 1234321 = 2280^2 + 1111^2 .

It is a cyclic number.

It is not a de Polignac number, because 6432721 - 2¹³ = 6424529 is a prime.

It is not a weakly prime, because it can be changed into another prime (6432421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3216360 + 3216361.

It is an arithmetic number, because the mean of its divisors is an integer number (3216361).

Almost surely, 2^6432721 is an apocalyptic number.

It is an amenable number.

6432721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6432721 is an equidigital number, since it uses as much as digits as its factorization.

6432721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 25.

The square root of 6432721 is about 2536.2809386974. The cubic root of 6432721 is about 185.9794269456.

It can be divided in two parts, 643 and 2721, that added together give a square (3364 = 58²).

The spelling of 6432721 in words is "six million, four hundred thirty-two thousand, seven hundred twenty-one".