442135621 has 4 divisors (see below), whose sum is σ = 442807200. Its totient is φ = 441464044.

The previous prime is 442135591. The next prime is 442135649. The reversal of 442135621 is 126531244.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 442135621 - 2¹³ = 442127429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 442135621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (442135121) 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, 334801 + ... + 336118.

It is an arithmetic number, because the mean of its divisors is an integer number (110701800).

Almost surely, 2^442135621 is an apocalyptic number.

It is an amenable number.

442135621 is a deficient number, since it is larger than the sum of its proper divisors (671579).

442135621 is an equidigital number, since it uses as much as digits as its factorization.

442135621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671578.

The product of its digits is 5760, while the sum is 28.

The square root of 442135621 is about 21027.0212108135. The cubic root of 442135621 is about 761.8190619183.

Adding to 442135621 its reverse (126531244), we get a palindrome (568666865).

The spelling of 442135621 in words is "four hundred forty-two million, one hundred thirty-five thousand, six hundred twenty-one".