442224721 has 2 divisors, whose sum is σ = 442224722. Its totient is φ = 442224720.

The previous prime is 442224719. The next prime is 442224737. The reversal of 442224721 is 127422244.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 389865025 + 52359696 = 19745^2 + 7236^2 .

It is a cyclic number.

It is not a de Polignac number, because 442224721 - 2¹ = 442224719 is a prime.

Together with 442224719, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 442224721.

It is not a weakly prime, because it can be changed into another prime (442224701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221112360 + 221112361.

It is an arithmetic number, because the mean of its divisors is an integer number (221112361).

Almost surely, 2^442224721 is an apocalyptic number.

It is an amenable number.

442224721 is a deficient number, since it is larger than the sum of its proper divisors (1).

442224721 is an equidigital number, since it uses as much as digits as its factorization.

442224721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7168, while the sum is 28.

The square root of 442224721 is about 21029.1398064685. The cubic root of 442224721 is about 761.8702328834.

Adding to 442224721 its reverse (127422244), we get a palindrome (569646965).

The spelling of 442224721 in words is "four hundred forty-two million, two hundred twenty-four thousand, seven hundred twenty-one".