403721 has 2 divisors, whose sum is σ = 403722. Its totient is φ = 403720.

The previous prime is 403717. The next prime is 403729. The reversal of 403721 is 127304.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 384400 + 19321 = 620^2 + 139^2 .

It is a cyclic number.

It is not a de Polignac number, because 403721 - 2² = 403717 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 403721.

It is not a weakly prime, because it can be changed into another prime (403729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201860 + 201861.

It is an arithmetic number, because the mean of its divisors is an integer number (201861).

2⁴⁰³⁷²¹ is an apocalyptic number.

It is an amenable number.

403721 is a deficient number, since it is larger than the sum of its proper divisors (1).

403721 is an equidigital number, since it uses as much as digits as its factorization.

403721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 403721 is about 635.3904311524. The cubic root of 403721 is about 73.9083965134.

The spelling of 403721 in words is "four hundred three thousand, seven hundred twenty-one", and thus it is an iban number.