521855449 has 2 divisors, whose sum is σ = 521855450. Its totient is φ = 521855448.

The previous prime is 521855447. The next prime is 521855473. The reversal of 521855449 is 944558125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 422713600 + 99141849 = 20560^2 + 9957^2 .

It is a cyclic number.

It is not a de Polignac number, because 521855449 - 2¹ = 521855447 is a prime.

Together with 521855447, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (521855447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260927724 + 260927725.

It is an arithmetic number, because the mean of its divisors is an integer number (260927725).

Almost surely, 2^521855449 is an apocalyptic number.

It is an amenable number.

521855449 is a deficient number, since it is larger than the sum of its proper divisors (1).

521855449 is an equidigital number, since it uses as much as digits as its factorization.

521855449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288000, while the sum is 43.

The square root of 521855449 is about 22844.1556858642. The cubic root of 521855449 is about 805.1004588953.

The spelling of 521855449 in words is "five hundred twenty-one million, eight hundred fifty-five thousand, four hundred forty-nine".