442115621 has 4 divisors (see below), whose sum is σ = 446673612. Its totient is φ = 437557632.

The previous prime is 442115581. The next prime is 442115629. The reversal of 442115621 is 126511244.

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 252364996 + 189750625 = 15886^2 + 13775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-442115621 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 (442115629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2278850 + ... + 2279043.

It is an arithmetic number, because the mean of its divisors is an integer number (111668403).

Almost surely, 2^442115621 is an apocalyptic number.

It is an amenable number.

442115621 is a deficient number, since it is larger than the sum of its proper divisors (4557991).

442115621 is an equidigital number, since it uses as much as digits as its factorization.

442115621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4557990.

The product of its digits is 1920, while the sum is 26.

The square root of 442115621 is about 21026.5456268974. The cubic root of 442115621 is about 761.8075747861.

Adding to 442115621 its reverse (126511244), we get a palindrome (568626865).

The spelling of 442115621 in words is "four hundred forty-two million, one hundred fifteen thousand, six hundred twenty-one".