442781721 has 12 divisors (see below), whose sum is σ = 663261872. Its totient is φ = 295187652.

The previous prime is 442781699. The next prime is 442781723. The reversal of 442781721 is 127187244.

It is not a de Polignac number, because 442781721 - 2⁷ = 442781593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (442781723) 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 in 11 ways as a sum of consecutive naturals, for example, 910831 + ... + 911316.

Almost surely, 2^442781721 is an apocalyptic number.

It is an amenable number.

442781721 is a deficient number, since it is larger than the sum of its proper divisors (220480151).

442781721 is an equidigital number, since it uses as much as digits as its factorization.

442781721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1822162 (or 1822150 counting only the distinct ones).

The product of its digits is 25088, while the sum is 36.

The square root of 442781721 is about 21042.3791668148. The cubic root of 442781721 is about 762.1899675170.

The spelling of 442781721 in words is "four hundred forty-two million, seven hundred eighty-one thousand, seven hundred twenty-one".