442442021 has 6 divisors (see below), whose sum is σ = 514677510. Its totient is φ = 379235976.

The previous prime is 442441991. The next prime is 442442023. The reversal of 442442021 is 120244244.

It can be written as a sum of positive squares in only one way, i.e., 409252900 + 33189121 = 20230^2 + 5761^2 .

It is a de Polignac number, because none of the positive numbers 2^k-442442021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (442442023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4514666 + ... + 4514763.

It is an arithmetic number, because the mean of its divisors is an integer number (85779585).

Almost surely, 2^442442021 is an apocalyptic number.

It is an amenable number.

442442021 is a deficient number, since it is larger than the sum of its proper divisors (72235489).

442442021 is an equidigital number, since it uses as much as digits as its factorization.

442442021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9029443 (or 9029436 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 23.

The square root of 442442021 is about 21034.3058121726. The cubic root of 442442021 is about 761.9950014943.

Adding to 442442021 its reverse (120244244), we get a palindrome (562686265).

The spelling of 442442021 in words is "four hundred forty-two million, four hundred forty-two thousand, twenty-one".