442686521 has 2 divisors, whose sum is σ = 442686522. Its totient is φ = 442686520.

The previous prime is 442686493. The next prime is 442686523. The reversal of 442686521 is 125686244.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 442471225 + 215296 = 21035^2 + 464^2 .

It is a cyclic number.

It is not a de Polignac number, because 442686521 - 2⁶ = 442686457 is a prime.

Together with 442686523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (442686523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221343260 + 221343261.

It is an arithmetic number, because the mean of its divisors is an integer number (221343261).

Almost surely, 2^442686521 is an apocalyptic number.

It is an amenable number.

442686521 is a deficient number, since it is larger than the sum of its proper divisors (1).

442686521 is an equidigital number, since it uses as much as digits as its factorization.

442686521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92160, while the sum is 38.

The square root of 442686521 is about 21040.1169435914. The cubic root of 442686521 is about 762.1353388799.

The spelling of 442686521 in words is "four hundred forty-two million, six hundred eighty-six thousand, five hundred twenty-one".