442721 has 2 divisors, whose sum is σ = 442722. Its totient is φ = 442720.

The previous prime is 442703. The next prime is 442733. The reversal of 442721 is 127244.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250000 + 192721 = 500^2 + 439^2 .

It is a cyclic number.

It is not a de Polignac number, because 442721 - 2¹⁰ = 441697 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 442693 and 442702.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 442721.

It is not a weakly prime, because it can be changed into another prime (442781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221360 + 221361.

It is an arithmetic number, because the mean of its divisors is an integer number (221361).

2⁴⁴²⁷²¹ is an apocalyptic number.

It is an amenable number.

442721 is a deficient number, since it is larger than the sum of its proper divisors (1).

442721 is an equidigital number, since it uses as much as digits as its factorization.

442721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 448, while the sum is 20.

The square root of 442721 is about 665.3728278191. The cubic root of 442721 is about 76.2155124877.

Adding to 442721 its reverse (127244), we get a palindrome (569965).

The spelling of 442721 in words is "four hundred forty-two thousand, seven hundred twenty-one", and thus it is an iban number.