442021421 has 4 divisors (see below), whose sum is σ = 442711644. Its totient is φ = 441331200.

The previous prime is 442021409. The next prime is 442021423. The reversal of 442021421 is 124120244.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 184579396 + 257442025 = 13586^2 + 16045^2 .

It is a cyclic number.

It is not a de Polignac number, because 442021421 - 2¹⁸ = 441759277 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 442021393 and 442021402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (442021423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 344150 + ... + 345431.

It is an arithmetic number, because the mean of its divisors is an integer number (110677911).

Almost surely, 2^442021421 is an apocalyptic number.

It is an amenable number.

442021421 is a deficient number, since it is larger than the sum of its proper divisors (690223).

442021421 is an equidigital number, since it uses as much as digits as its factorization.

442021421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 690222.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 442021421 is about 21024.3054819892. The cubic root of 442021421 is about 761.7534657345.

Adding to 442021421 its reverse (124120244), we get a palindrome (566141665).

The spelling of 442021421 in words is "four hundred forty-two million, twenty-one thousand, four hundred twenty-one".