442521997 has 2 divisors, whose sum is σ = 442521998. Its totient is φ = 442521996.

The previous prime is 442521977. The next prime is 442522009. The reversal of 442521997 is 799125244.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 313608681 + 128913316 = 17709^2 + 11354^2 .

It is a cyclic number.

It is not a de Polignac number, because 442521997 - 2²³ = 434133389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442521907) 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 as a sum of consecutive naturals, namely, 221260998 + 221260999.

It is an arithmetic number, because the mean of its divisors is an integer number (221260999).

Almost surely, 2^442521997 is an apocalyptic number.

It is an amenable number.

442521997 is a deficient number, since it is larger than the sum of its proper divisors (1).

442521997 is an equidigital number, since it uses as much as digits as its factorization.

442521997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The square root of 442521997 is about 21036.2068111150. The cubic root of 442521997 is about 762.0409115704.

The spelling of 442521997 in words is "four hundred forty-two million, five hundred twenty-one thousand, nine hundred ninety-seven".