442202021 has 2 divisors, whose sum is σ = 442202022. Its totient is φ = 442202020.

The previous prime is 442202017. The next prime is 442202027. The reversal of 442202021 is 120202244.

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., 432057796 + 10144225 = 20786^2 + 3185^2 .

It is a cyclic number.

It is not a de Polignac number, because 442202021 - 2² = 442202017 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442202027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221101010 + 221101011.

It is an arithmetic number, because the mean of its divisors is an integer number (221101011).

Almost surely, 2^442202021 is an apocalyptic number.

It is an amenable number.

442202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

442202021 is an equidigital number, since it uses as much as digits as its factorization.

442202021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 442202021 is about 21028.6000722825. The cubic root of 442202021 is about 761.8571967132.

Adding to 442202021 its reverse (120202244), we get a palindrome (562404265).

The spelling of 442202021 in words is "four hundred forty-two million, two hundred two thousand, twenty-one".